Industry chiefs have rallied against planned reforms to the Official Secrets Act which it is warned “could criminalise public interest journalism”.

The News Media Association has declared its opposition to the proposals, saying they could expose journalists and whistleblowers to “harsh new penalties such as lengthy prison sentences”.

Under a consultation run by the Home Office, which closes later today, reporters who handle leaked documents would not have a defence if charged under the laws.

The NMA has joined human rights organisations and the Law Commission in calling for a ‘public interest’ defence to counter the effects of the planned legislation – but the Home Office has claimed such a move “could undermine our efforts to prevent damaging unauthorised disclosures, which would not be in the public interest”.

NMA legal policy and regulatory affairs director Sayra Tekin, pictured, said: “As part of any thriving democracy, the public and a responsible press must be free to shed light on the state’s injustices.

“The proposed measures will deter whistleblowers from coming forward with vital information which the public have a right to know and place a chill on investigative journalism which holds power to account.

“We strongly urge the Government to reconsider these measures and instead work with the industry to place appropriate protections for journalism at the heart of the Official Secrets Act so that freedom of speech is enhanced by the new regime rather than weakened further.”

The NMA also opposes any increase in severity of sentences as this would “inadvertently worsen the already weak position of journalists and whistle-blowers through harsher sentencing.”

Instead, the trade body for the regional and national press says the regime should be changed to introduce an “absolutely essential” public interest defence to the Official Secrets Act which would enable matters of public interest to be properly scrutinised and debated.

A Home Office spokesman told the Daily Mail: “Freedom of press is an integral part of the UK’s democratic processes and the government is committed to protecting the rights and values that we hold so dear.

“It is wrong to claim the proposals will put journalists at risk of being treated like spies and they will, rightly, remain free to hold the government to account.

“We will introduce new legislation so security services and law enforcement agencies can tackle evolving state threats and protect sensitive data.

“However, this will be balanced to protect press freedom and the ability for whistleblowers to hold organisations to account when there are serious allegations of wrongdoing.”