They cite his plunging popularity and strained ties with lawmakers, and believe he will struggle to adapt to civil servants' working styles and the government's operation.

Leung dusted off his campaign slogan 'One heart, one vision for Hong Kong' as he named his team of senior officials on Thursday, and took the opportunity to reassure anxious and frustrated Hongkongers that he could lead the city through the challenges ahead.

'I know that the road ahead is bound to be rough and a lot of challenges are lying in store for us. However, we will not be daunted. I am confident that my team and I will overcome all difficulties and prove our commitment to Hong Kong through our deeds,' the 57-year-old said.

In recent days, a lack of support from some pro-establishment lawmakers scuttled plans to fast-track consideration of Leung's government restructuring, killing his hope of having his revamp completed by the time he took office. It means his candidates to fill four new roles will not be able to be sworn in before President Hu Jintao today.

But he remains confident: 'Together, we, the fourth-term government, will bring positive changes to Hong Kong and live up to public expectations.'

Dismissing charges that the pace of change may be too quick, he said: 'In the next five years, we will make prudent adjustments and seek changes while maintaining stability.'

Leung dismisses claims that he is a closet communist, but that has done little to ease concerns about the erosion of freedom of speech, expression and assembly under his rule.

'We will safeguard the core values that we have treasured for years, resolve deep-seated conflicts, improve the livelihood of our people and work towards the harmony and stability of our society,' he said on Thursday.

Leung, hailed as someone who can bring hope to the city's poorest in the face of widening income inequality and lack of opportunity, also said: 'It is our common wish to devote ourselves to changing the prolonged sluggishness of our economic and social development.'

But Leung's positive words failed to convince everyone. Many political scientists believe he - and the city - face a rocky road ahead.

'Leung Chun-ying has vowed to deal with many livelihood issues and people have high expectations of him,' Chan Kin-man, an associate professor of sociology at Chinese University, said.

'[Years ago,] Tung also had policies in mind. But he could not handle his relationship with civil servants well and lacked partners in the Legislative Council and the community, so he failed to put [many of] his policies into effect,' Chan said. Leung could face similar difficulties, he said.

One factor that will not help Leung is the divide in the Beijing loyalist camp between his supporters and those who favoured Henry Tang Ying-yen, long the favourite for the top job until scandals surrounding the former chief secretary - including one involving illegal structures - gave Leung the edge.

'In Legco, his ties with the Liberal Party seem bad. They didn't vote for him in the [chief executive] election,' Chan said. 'In future, the Democratic Alliance for the Betterment and Progress of Hong Kong and the Federation of Trade Unions might not fully support his controversial policy initiatives either.'

Chan says Leung's approach to the pan-democratic camp has also shown early signs of problems.

'Leung wants to put pressure on pan-democrats by appealing directly to society, as shown in his calls for the masses to speak out on lawmakers' filibuster on the by-election bill,' he said, referring to an attempt by some radical legislators to talk out a proposal to ban lawmakers who resign from contesting by-elections for six months.

'He wanted them to express their discontent, but failed to mobilise many people to come out in the end ... Instead, his move left pan-democrats disgusted. In his attempt to get his revamp proposal fast-tracked in the legislature, he initially wanted to suppress pan-democrats' opposition by winning over the public but his efforts went in vain,' Chan added. 'It is foreseeable that the situation will worsen. There will be hardly any room for him to [indirectly pressure] the legislature by making use of public opinion.'

A poll conducted by Chinese University's Institute of Asia-Pacific Studies found that Leung was the most popular with the less well-off, the elderly and the less educated.

'The public is polarised,' Chan said. 'The grass roots throws more support behind him while intellectuals are uneasy. If the funding requests of his administration are blocked in Legco and his promises cannot be delivered, the grass roots will have no reason to continue standing by him. If he fails to properly handle his relationship with Legco, he might not be able to address livelihood issues.'

Chan expects Leung to hold off on addressing controversial issues such as electoral arrangements for the 2016 Legco polls for the time being.

Paul Wong Chi-wai, a social studies lecturer at City University's Community College, shares the concern about Leung's prospects, saying: 'He does not have a honeymoon period, but faces a huge crisis.

'To make a ruling coalition succeed, a prerequisite is that the chief executive should have goodwill, integrity and credibility. He should also be able to balance the interests and demands of different factions. But as Leung was [allegedly] groomed for this position by [the central government's liaison office in Hong Kong], there is a big doubt as to whether his coalition can be inclusive. Even if there are pro-establishment representatives in the Executive Council, there won't be a 100 per cent guarantee that they will support the government at the critical moment,' he said.

Wong also said it would not be easy for Leung to recruit the Democratic Party as an ally, as such an alliance could affect the party's prospects. He believes Leung will try to maintain stability by keeping allies of Tang in their posts on the boards of public bodies or consultative panels in the first few years of his term.

Pundit James Sung Lap-kung says September's Legco election will be on the minds of some of Leung's potential allies. 'With the Legco polls around the corner, it seems that many pro-establishment parties and factions, like the Democratic Alliance for the Betterment and Progress of Hong Kong, the Federation of Trade Unions, the Liberal Party and the New People's Party, dare not to be close to him amid fear that their popularity could be dragged down,' the academic co-ordinator at City University's School of Continuing and Professional Education said.

The fact that many Legco seats are likely to change hands in September means it remains uncertain when or even if Leung's government revamp will be approved.

So far, five of Leung's 15 top aides are new to the government - Secretary for Justice Rimsky Yuen Kwok-keung, Secretary for Transport and Housing Professor Anthony Cheung Bing-leung, Secretary for Education Eddie Ng Hak-kim, Secretary for Food and Health Dr Ko Wing-man and Secretary for the Environment Wong Kam-sing.

'He himself has no experience of public administration. There could be many different voices in his cabinet. It will be a tough test for him to lead a team of people from different backgrounds,' Sung said.

'The failure to have his whole cabinet, including two deputy secretaries [to aid the chief secretary and the financial secretary] and two new ministers, come on board on July 1 might also affect the government's operation, particularly on the drafting of October's policy address.'

He urged Leung to be cautious in handing out sweeteners in his maiden policy address despite the rising tide of public discontent.

The latest poll by the University of Hong Kong's public opinion programme saw Leung's support rating slide to a new low of 51.3 points out of 100, down 2.8 points in three weeks.

By comparison, Tsang's rating was 72.3 points when he took office after Tung stood down in late June 2005. 'With low popularity, Leung's government is now in a weak position,' Sung said. 'Whether he can stem [the fall in] support will partly depend on whether he can completely defuse the political bomb of the illegal structures at his home and convince people that he did not lie [about them]. It is very challenging.'

Sung suggested the new administration could boost its standing by living up to its pre-election promises to increase the supply of subsidised housing as soon as possible.

Beijing might also have a role to play, Sung said, perhaps by boosting efforts to block at the border the influx of mainland mothers-to-be, an issue which has angered many Hongkongers.

On the economic front, Sung said it would take time for Leung's pledge to foster the development of different industries to bear fruit, while the European debt crisis cast a long shadow.

Wong said expectations that Leung would tackle the city's over-reliance on the real estate and financial services sectors would be difficult to meet. 'We'll have to wait and see if his government can cool down the overheated property market and make a soft landing for house prices happen,' he said.

70%

The number of respondents to a poll who believe the illegal structures scandal has hurt Leung Chun-ying's integrity

Hot potatoes

What Leung must do

On constitutional development

- decide the electoral methods for the 2016 Legislative Council election

- implement universal suffrage for the 2017 chief executive election, paving the way for universal suffrage in the 2020 Legco poll

- scrap appointed seats on district councils in 2016

On mainlanders giving birth in Hong Kong

- decide on legislative and/or executive measures to further curb the tide of mainlanders giving birth in the city

- study seeking interpretation of the Basic Law from the National People's Congress Standing Committee

- amend the Basic Law or the Immigration Ordinance

- require mainland women to get medical endorsements before coming to the city to give birth

On national security legislation

- decide if and when to propose legislation under Article 23 of the Basic Law and what will be regulated

On the widening income gap

- work out how to improve the livelihood of the poor, perhaps through the newly revived Commission on Poverty

On illegal structures

- stamp out unauthorised structures across the city, despite the strong opposition from indigenous villagers in the New Territories

On Government Hill

- decide whether to preserve the west wing of the old government headquarters in Central

On Ho Tung Gardens

- decide the fate of historic mansion on The Peak in view of the owner's objection to a plan to declare the site a monument

On housing needs and land supply

- speed up the building of public rental housing and provide more Home Ownership Scheme flats

- work out ways to increase land supply, perhaps by further exploring the feasibility of land reclamation outside Victoria Harbour

On the copyright bill

- decide whether and to what extent to revise the controversial copyright bill and when to table it to Legco again after the last administration shelved it

On national education

- oversee the government's plan to introduce a controversial course in moral and national education to public primary schools in 2015 and to public secondary schools in 2016

On economic uncertainty

- boost the development of different industries