Ministers have exempted thousands of scientists from a controversial “gagging clause” that would have prevented the academics from trying to influence government on public policy matters.

The move follows intense pressure from the scientific community to amend proposals drawn up by the Cabinet Office to stop organisations, mostly charities, from using taxpayer-funded grants to lobby the government or parliament.



The ban, which comes into effect on 1 May, threatened to silence academics and exclude them from public debates as diverse as energy, climate change and transport policies.



But speaking in the House of Lords on Tuesday, Lord Bridges of Headley, the parliamentary secretary for the Cabinet Office, announced exemptions for major government-backed funding bodies, including the research councils, the national academies and the Higher Education Funding Council for England.



Martin Rees, the astronomer royal, welcomed the move but criticised ministers for taking so long to clarify the proposals after they were first made public in February.



“This clarification is welcome but should have come sooner. It’s regrettable that it was preceded by months of confusion and ambiguity that generated needless anxiety, ill-feeling and time-wasting,” he said. Nearly 20,000 academics signed a petition calling for scientists to be exempt from the ban.



Sarah Main, the director of the Campaign for Science and Engineering, said the announcement was good news and a “huge step” in the right direction. “Scientists felt embroiled in a debate about lobbying which did not appear to apply to them,” she said. “We now need to get the detail right to make sure this solution works for all of government and all of science.”



But some in the community criticised the exemption for not going far enough. Imprecisely worded, it does not exclude scientists directly funded by government through departments such as health, business and defence.



Mark Maslin, a climatologist at University College London, said the independence of a country’s scientific expertise was central to the freedoms demanded by a modern democracy.



“If government or commerce, whether inadvertent or knowingly, put people at risk then scientists must be free to sound the warning bells without the risk of censure or legal proceedings. By rights the government should be granting a full exemption to all scientists sending a clear message that scientific knowledge is above petty party politics and is there for the betterment of all citizens,” he said. “What we have is a mess with an imprecise exemption which does not ensure that all scientists can criticise the government with impunity.”