Britain's 24 nanotechnology centres could be among the casualties of cuts to the UK science budget, science minister David Willetts has said.

The previous government spent £50m on the network of research facilities at universities across the UK.

But Mr Willetts told MPs there were too many small "sub-critical" research centres and they should be centralised.

He said it was "most unlikely" the nanotech centres would still be open in 18 months.

Mr Willetts told the science and technology committee on Thursday that he was in negotiations with the Treasury about what would be axed from the science budget in October's comprehensive spending review.

In common with other government departments, science is facing cuts of between 25% and 40%.

Following consultation with Britain's "learned societies," such as the Royal Society, Mr Willetts said he had written to the Treasury to indicate areas of research where funding could be cut.

'Blue skies research'

There is concern that cuts could damage areas of research, such as particle physics, which have no short-term economic benefit.

Mr Willetts told the committee he was determined to protect "blue skies" scientific research in the UK but also wanted to avoid simply drawing up a list of "sexy sounding" subjects, such as biotech or space, to be protected from cuts, as this had proved to be the wrong approach in the past.

Instead, there would be a more rigorous analysis of what should be protected, he told the MPs.

Nanotechnology spans different areas of science including chemistry, engineering and biosciences.

It promises to radically reduce the size of computers and produce materials that strengthen and lighten bridges and planes.

When the final five nanotech centres were opened in 2006, the then science minister Lord Sainsbury said: "The UK has created a world-leading network of facilities that will significantly increase industry's ability to exploit nanotechnology."