Big reductions in the UK's scientific research capacity will be necessary if planned 25% cuts to government spending in the sector go ahead, the director of one of the country's main science funding bodies warned tonight.

John Womersley, director of science programmes at the Science and Technology Facilities Council (STFC), told the Guardian it would not be possible to achieve such deep cuts without mothballing a major facility.

He said those at risk included particle accelerators such as the £383m Diamond Light Source, which opened only three years ago, and the £145m Isis neutron source. Both are in Oxfordshire.

Officials from the STFC fear the cuts may also jeopardise Britain's involvement in Cern, the Geneva-based home of the Large Hadron Collider particle research project, documents seen by the Guardian show.

There are also warnings that an almost £1bn cut to the £3.5bn science research budget would entail the loss of significant numbers of postgraduate and post-doctoral researchers, creating a "lost generation" of scientists and engineers and draining innovation from the economy.

Any of these steps would amount to "vandalism", according to Professor Brian Cox, the broadcaster and professor of particle physics at the University of Manchester. "Mothballing of Diamond or Isis, or withdrawal from Cern – any of these courses of action would irreparably damage physics in the UK at all levels," he said.

The take-up of science in schools and universities would be hit, as would the UK's ability to participate in future global scientific projects, he added. "Not to mention the massive waste of taxpayers' money involved in building facilities and then withdrawing from them on the eve of their scientific return. It would be madness, vandalism even, at every level."

Britain has been leading an attempt by the 20 member nations at Cern to cut its budget by £215m, which may force its experiments to halt for a year in 2012.

Diamond and Isis, which cost respectively £28m and £35m a year to run, contain machines that act as giant microscopes to allow scientists to examine the inner structure and behaviour of proteins and atoms in real time in three dimensions.

They employ 800 scientists between them and hundreds of scientific papers have been published based on their work on a range of subjects from biomedical and forensic science to aerospace, pharmaceuticals and archaeology.

A complete pullout from Cern would, however, be difficult because there would be heavy financial penalties which were embedded in the original agreements.

Imran Khan, director of the Campaign for Science and Engineering (CaSE) said it would be a "ridiculous waste of money if Diamond were to be mothballed – like building the Olympic stadium and then not using it".

Womersley said: "At some funding level, between where we are now and having half as much money, we would no longer be able to operate both Isis and Diamond as big facilities in the UK. We would clearly regard [leaving Cern] as a serious step. [However] this is a government that wants to discuss … the value of all aspects of a programme, and we shouldn't assume anything is off the table."

Last year, funding problems at the STFC, the body that allocates public spending in astronomy, particle and nuclear physics, and space science, meant that cash for Isis and Diamond had already been slashed: Isis only had enough money to operate for around 120 days this year, approximately half its capacity. But, because the baseline costs of the facility were so great, the move only saved around 5% of the annual budget.

Cox said scientists were already in a weak position for the spending review because of funding mistakes made under the Labour government. "This is why even a modest reduction in funding for physics will result in a catastrophe," he said.

At a recent policy meeting held at the Institute of Physics between research councils and scientists, the Engineering and Physical Sciences Research Council suggested the worst-case scenario would see it rescind up to £135m of grants that have already been awarded.

Notes from the meeting, seen by the Guardian, said the deepest cuts would mean the STFC could be forced to consider "withdrawal from a major facility … eg Cern". The STFC is already negotiating a reduction of its £70m annual subscription to Cern but any decision to withdraw completely would have to be taken by ministers, and would be seen as a serious dent in the UK's international standing in science.

The government distributed £3.5bn to researchers through the science budget in 2007-08. Under a 25% cut, that could drop to £2.6bn, with savings coming from fewer grants for researchers, a reduction in PhDs and big cuts to infrastructure. "A 25% cut actually means an even bigger cut in the number of new grants issued, because the research councils have less money with which to honour their existing multi-year grants," said Khan. "It could completely change the landscape of UK science."

Womersley said a lot of the science funded by STFC was long-term or unpredictable in its practical outcomes, citing examples such as superconducting magnets for medical imaging, and the world wide web. "One way we can have a big impact to help the economy is by training people – young people being attracted into physics, engineering and tech and those people going out into the workforce."

But even that could be at risk. "If we have 25% cuts and you want to protect every major facility or project – like Diamond, Isis, Cern, the National Physical Laboratory, the British Antarctic Survey, the Geological Survey – then you might be able to do that, but it will come at the cost of research grants and studentships," said Khan. "We could see a lost generation of scientists and engineers, with there being insufficient PhD and post-doctoral places for hugely talented individuals."

He added: "Our competitor nations such as Germany and the US are investing in science and engineering right now because they recognise that they stimulate economic growth and can help to rebalance the economy. It is pretty obvious that if the UK does the exact opposite, those companies will look elsewhere. That would deepen the deficit – in a recession you need to invest in science and engineering to reap the benefits, not cut back."

A spokesman for the Department for Business, Innovation and Skills said it was "unhelpful to speculate on the spending review while the process continues. The government recognises the key role research, technology and innovation will play in rebalancing the economy and wants science to emerge from these tough economic times to be strong, sustainable and effective. We are strongly committed to making the economic case for science."

The spokesperson added: "But public spending on science, just like everything else has to stand up to rigorous economic scrutiny. In these austere times, the public should expect nothing less."

Projects at risk



Diamond Light Source

Synchrotron light is created by accelerating electrons to produce beams of x-rays, ultraviolet and infrared rays. Researchers at the Oxfordshire facility can use these to study samples at an atomic and molecular level. The light from Diamond has been used in everything from basic research into the understanding of diseases such as Parkinson's and cancer to pandemic flu and HIV. Hundreds of protein structures have been analysed here and more than 430 scientific papers have been written using Diamond data in the past two years.

Isis

This facility, an Oxfordshire neighbour of Diamond, uses beams of neutrons to probe the tiniest 3D structures. Neutrons can give information on the location and movement of light atoms such as hydrogen and lithium, which are not so easy to see with x-rays.

The beams from Isis were used to help in the design of the ultra-strong and ultra-light materials used in the wings of the Airbus A380 aircraft. First opened in 1985, the facility employs about 400 staff and hosts about 2,000 scientists from 30 countries every year, who between them produce in excess of 400 scientific papers. A large expansion at a cost of £145m to the taxpayer was recently completed.

Cern

The international particle physics laboratory in Geneva is the birthplace of the world wide web and now home to the Large Hadron Collider, the 17-mile particle accelerator that smashes protons together to recreate the moments after the big bang. By examining the remnants of the collisions, scientists want to investigate the fundamental constituents of matter and look for the origins of mass and evidence of extra dimensions.

Economic spinoffs

According to the Campaign for Science and Engineering, every £1 spent on public or charitably funded research has given a return of 30p a year in perpetuity from direct or indirect GDP gains, on top of the direct gains of the research. From 2003 to 2007, 31 university "spin-outs" were floated on stock exchanges, with an initial value of £1.5bn, and 10 spin-outs were bought for a total of £1.9bn.

Alok Jha