Parliament is to consider a change in the law which would tackle the issues raised by Press Gazette's Save Our Sources campaign.
Liberal Democrat peer Lord Strasburger has tabled an amendment to the Serious Crime Bill that would require public authorities to ask a judge before accessing the phone records of journalists.
The Liberal Democrats are seeking cross-party support for the amendment in the hope that it can get the backing of the Government when the bill returns to the commons.
Strasburger said: “There is no good reason why phone records which may disclose a journalist’s source should not be subject to the same safeguards under RIPA as they enjoy under the Police and Criminal Evidence act 1984 (PACE) and this amendment brings RIPA into line with PACE.
"The Liberal Democrats are serious about protecting whistleblowers and the freedom of the press to expose corruption through the use of confidential sources. RIPA must be changed to close the loophole in RIPA that the police have been using with virtually no scrutiny.
"The whole spectrum of the newspaper industry have united behind the impressive 'Save Our Sources' campaign by the Press Gazette which also has the support of legal experts, civil liberties groups and working journalists.
"Of course this is not the only major flaw in RIPA and I wish more newspapers had backed The Guardian when it exposed the widespread collection by the state of phone and other records of ordinary citizens through the Tempora Project and other secret surveillance activities.”
So far some 1,200 editors, journalists, press freedom campaigners and others have signed the Save Our Sources petition calling for urgent action to stop public authorities using RIPA spying powers on law-abiding journalists and their sources.
The campaign was prompted by the revelation that the Met had secretly seized the phone records of The Sun in order to find and sack three officers accused of leaking information about the Plebgate affair. The Crown Prosecution Service said the three officers had no case to answer.
Since then it has emerged that Kent Police used RIPA to obtain the phone records of journalists working for The Mail on Sunday and Suffolk Police used it against a journalist working for the Ipswich Star. In neither case were the journalists suspected of breaking the law.
In 2006, Thames Valley Police used RIPA spying powers to tape conversations between local newspaper journalist Sally Murrer and a police contact. They sought permission for the bug from the relevant outside authority but are understood to have failed to declare that Murrer was a journalist.
The Home Office is set to consult in the coming weeks on changes to the RIPA code of practice which it has said will give greater protection to journalists.
But Press Gazette understands that the intention is that even under the new tougher guidance, police forces could still sign off RIPA requests against journalists themselves.
The RIPA amendment has been tabled for discussion at the report stage of the bill in the House of Lords on 28 October.
The amendment says law enforcement officers must obtain the approval of a judge in order to seize communications data which could identify journalistic sources or involve legally privileged information.
Under the amendment such applications for data would be excluded from the usual process of internal authorisation, and instead be subject to the approval of a judge.
The proposed change to the law is said to be a “probing amendment” meaning that it won't be voted on it this stage but it is hoped the Government will consider it and return with a view later in the bill's progress.