Press reform campaign group Hacked Off claims more than 6,000 people have signed its petition calling on the Government to refuse a request from the Times and Sunday Times to change its editorial independence rules.
The group has said it fears the quality and integrity of the two newspapers would be put at risk by the move and “pave the way for redundancies”.
News UK, which owns both titles, has said it is seeking a “small change” to undertakings put in place when Rupert Murdoch bought them in 1981 that ensures they each have their own editor, editorial teams and newsrooms.
The conditions require that journalists and other resources are kept separate between the Times and Sunday Times.
News UK has said it is committed to both titles remaining separate, with separate editors, but said the change would allow for more “flexibility to share resources” and avoid duplication.
It also pointed to its need “to contend with the continual disruption that has faced the media industry in the digital age”.
However, Hacked Off will make a submission to the Department for Digital, Culture, Media and Sport’s consultation raising fears that quality will be put at risk if journalists are shared between the two titles.
It believes any strategy to share journalists will inevitably result in job cuts and see remaining staff stretched between the Times and Sunday Times with an increased workload.
News UK has previously declined to comment on any potential staffing cuts.
Hacked Off, which was founded in the wake of the phone-hacking scandal, also fears that sharing reporters and columnists will see the content of the two titles brought closer together, jeopardising plurality.
Its final concern is that there will be a less effective deterrent for breach of the conditions.
The existing agreement comes under the Fair Trading Act 1973, with a maximum punishment of two years’ imprisonment and a fine for knowingly breaching the conditions.
But any update will see the agreement revert to the Communications Act 2003 and stop it being a criminal offence, with structural remedies instead coming through the Competition and Markets Authority for any breaches.
Hacked Off’s petition against the changes was launched on Thursday last week.
Nathan Sparkes, Hacked Off’s director of policy, said: “The proposed changes to the conditions attached to News UK’s ownership of Times titles would allow journalists to be rationed out across the two titles – paving the way for redundancies and jeopardising the quality of the papers.
“By sharing journalists, the two distinct investigatory agendas of the titles risk being consumed into one, which would erode plurality in the newspaper market.
“Most worryingly of all, the proposed changes would downgrade all of the conditions – including those which go to the heart of editorial independence at the titles – from cast-iron protections backed up by a criminal offence for any breach, to undertakings which are not supported by any criminal offence for breaches.
“Given repeated and well-substantiated allegations of owner-interference from Rupert Murdoch at Times newspapers in the past, this bid to water-down the existing defences against the Murdoch family’s editorial influence at the titles should be rejected out of hand.”
A Times spokesperson declined to comment, but editor John Witherow has previously said: “The persistent cost pressures facing our industry mean that we need to manage our newsrooms as carefully as possible.
“We need to stay competitive in an increasingly difficult market so that we can continue to build a sustainable future for Times journalism.”