A proposal by Hong Kong to allow Shenzhen's 2 million permanent residents to freely make multiple visits to the city is part of Chief Executive Donald Tsang Yam-kuen's vision for a cosmopolitan economy with up to 10 million people. A government source said yesterday that Hong Kong had 'reflected' the idea to the central government but it would be up to Beijing whether it went ahead, and it could take a long time to put into effect. The move, which would further integrate the two cities and make it easier to tap cross-border talent, has come to light after an interview by Mr Tsang with the Financial Times, in which he said the city should increase its population by 40 per cent to 10 million to compete with New York and London as a global financial centre. Government thinking is that Hong Kong's competitiveness hinges on a critical mass of quality human capital, and technologically advanced Shenzhen would be a good city to pair up with. The scheme would free Shenzhen residents from the need to apply to visit Hong Kong under the individual travel scheme and allow them more or less to come and go as they pleased, as Hongkongers now are allowed to in Shenzhen. They would either use their electronic identity cards or be issued with a special pass. It would be a breakthrough in travel between the mainland and Hong Kong, still subject to colonial-era restrictions 10 years after the handover. Shenzhen residents entering in this way would not immediately be allowed to work in Hong Kong. But the government source said making visits easier could encourage talented people to apply to work in the city under the Admission Scheme for Mainland Talents and Professionals or the Quality Migrant Admission Scheme. Former secretary for security Regina Ip Lau Suk-yee said the plan was being studied when she was in the post. The head of the China Business Centre at Hong Kong Polytechnic University, Thomas Chan Man-hung, said it would be a breakthrough in travel policy, which had been distorted under colonial rules. 'I cannot see grounds for keeping the restriction on mainland residents entering Hong Kong within their own country, while visa-free travel is offered to other countries,' he said. Dr Chan, a special researcher for the Guangdong government, said he had put forward the idea five years ago. Le Zheng , director of the Shenzhen Academy of Social Sciences, estimated that 300,000 Shenzhen residents would commute frequently if they were allowed to visit Hong Kong freely. 'We have advised the Hong Kong SAR government [to endorse this idea] for years. But we have not had much response until now,' he said. Federation of Trade Unions president and local deputy to the National People's Congress Wong Kwok-kin said the city could not handle a huge inflow of an extra 200,000 to 300,000 visitors even if the plan was carried out in phases.