In an ambitious speech that will alarm the anti-nuclear lobby, John Hutton, the business secretary, will argue that the UK's nuclear programme should go beyond replacing the existing stock of 23 reactors, which provide 20% of the country's energy. Instead nuclear should contribute "a significantly higher proportion" of the nation's energy needs in the years ahead, and Britain should aim to become a world leader in the development of nuclear power technology.

He will argue that replacing the existing reactors will be equivalent to investment "three times the size of the project to build Terminal 5 at Heathrow", but that the economic benefits could be far greater if Britain went further.

The speech, one of the most pro-nuclear delivered by a government minister, comes before an Anglo-French announcement to co-operate on the expansion of nuclear power. Hutton will say: "There has never been a greater global demand for finance, equipment and skills to build and operate nuclear power stations. I want Britain to be leading the world in the development and application of this new generation of low carbon power technology."