Financial Secretary John Tsang Chun-wah warned yesterday against "blindly" pursuing new industries to drive growth, suggesting "conventional economic pillars have their edge".
On his official blog, Tsang also said taxes may rise or more government bonds could be issued if the administration fails to keep its budget in the black.
He said while people always paid attention to public spending, they should not forget about government income.
He rejected criticism that Hong Kong had relied too much on the so-called pillar industries - finance, logistics and trade, tourism, and professional services.
His comments - ahead of Chief Executive Leung Chun-ying's maiden policy address - were challenged by economists for lacking long-term vision.
Tsang said: "We must understand that a new industry takes a long time to nurture and develop, and its success is not guaranteed.
"Therefore, we should not blindly pursue the development of new sectors and overlook the established pillar industries.
"The four conventional pillars have become our major economic backbone because they have the edge … While developing new sectors, we should make more effort to expand the edge of the pillar industries."
Tsang referred to the final shootout in the latest James Bond film Skyfall, in which a companion hands Bond a knife to fight the villains, telling him: "Sometimes the old ways are best."
Tsang said: "I believe 007 would agree that, whether it is a knife or a laser gun, it is a good weapon so long as it can be used to kill the enemy."
Tsang stressed the importance of the economy growing "sustainably" to support rising government spending.
And he emphasised the importance of prudential management of public finances.
"With an ageing population, it is unavoidable that we will have to pump in more resources in welfare and medical areas.
"If our economy cannot develop sustainably, it is likely the government will fall into deficits in the long run. And it will leave us with only two choices - either increase taxes or issue bonds."
Tsang denied the economy was too reliant on the pillar industries. He said the finance sector accounted for only 16 per cent of gross domestic product in 2010 and the four pillar industries combined accounted for about 58 per cent.
Professor Raymond So Wai-man, dean of Hang Seng Management College's school of business, said: "I agree it is easiest to follow the old ways. But for the long-term, we have to find new drivers for the economy."
Dr Li Kui-wai, an economist at City University, was surprised Tsang seemed to have departed from what Leung said during his election campaign.
Leung stressed the importance of diversification and developing "technology-based industries" to "enhance the competitiveness and growth of Hong Kong's other industries".