Francis Maude has been warned that changes to the civil service code threaten to stop thousands of publicly-funded scientists from expressing their views on some of the most pressing issues faced by modern society.

In a letter to the cabinet secretary on Friday, science organisations expressed their “deep concern” over recent amendments to the code, which demand that all civil servants, including government researchers, seek ministerial approval before they talk to the media.



They fear that the blanket restriction will make it nearly impossible for government experts to speak to journalists on issues as varied as GM crops, vaccines, infectious diseases and fracking, because ministers could take days or more to respond to the requests.



The revised code was introduced with immediate effect two days before the spring budget, and has been circulated to Britain’s research funding councils and government research laboratories. Among the government-funded centres affected by the changes are the Met Office, the Department for Transport’s Air Accidents Investigation Branch, and the National Institute for Biological Standards and Control.



Under the new code, scientists and engineers employed at government expense must get ministerial approval before they can talk to the media about any of their research, whether it involves GM crops, flu vaccines, the impact of pesticides on bees, or the famously obscure Higgs boson.



“We have seen a lot of political decisions made very rapidly that don’t translate into anything that is workable,” said Tony Bell at Prospect trade union, which is seeking clarifications on the changes. “They are using a sledgehammer to crack a nut. They don’t seem to have thought about the people out there who are doing science.”



The revised code has already angered the FDA, a union for senior civil servants, which branded the move draconian and intimidating.



The letter to Maude warns that by effectively silencing government scientists, the public will be left far less informed than before. “This will have a negative impact on the public understanding of science and the quality of the public discourse on some of the most important and contentious issues of our times,” it states.

“We urge the government to think again about this policy and its unintended and undesirable consequences,” the letter continues.



Sir Colin Blakemore, who signed the letter as the honorary president of the Association of British Science Writers, told the Guardian that under the revised code, it would be harder for the public to hear the evidence and opinions of scientists directly employed by the government.



“The real losers here are the public and the government. The public lose access to what they consider to be an important source of scientific evidence, and the government loses the trust of the public,” Blakemore said.



“It sends a message to the science community that the government is wary about scientists sharing their evidence and expressing their views in the media. And if that’s true, it contradicts the last 30 years of encouraging scientists to be more open.”



Fiona Fox, head of the Science Media Centre, who also signed the letter, said the revised code would have a “chilling effect” on government scientists who are often already cautious to speak to the media.



“The government is saying it doesn’t want its scientists to speak and that is going in completely the wrong direction. What we need are messages from on high that are supportive and back scientists sharing their evidence and expertise to better inform these debates,” she said. “Unless the situation is clarified, this will have a chilling effect. Scientists will keep quiet to be on the safe side.”



The cabinet office said that individual departments could apply for exemptions to the amendment.

“The minister has received the letter and will respond in due course,” a cabinet office spokesman said. “The recent amendment in the civil service code clarifies an existing requirement and will not impact the important and valuable role scientists play in the civil service.”

A request for comment from Sir Mark Walport, the government’s chief scientist, was referred back to cabinet office.

