The Associate Editor of The Sun Trevor Kavanagh has accused politicians of taking the press to the "brink of political control", a move he claims is a "bridge too far".
The final decision to reject the newspaper industry's plans for regulation is expected to be announced by Culture Secretary Maria Miller in the Commons later today.
Mr Kavanagh insisted three centuries of press freedom needed to be protected, before suggesting that a future government may decide the press is too free and enforce further restrictions and regulation.
He added: "It's what we'd been given fairly clear clues would happen. I think it has to be seen as a great victory for the forces of oppression of a free press - Hacked Off in particular - and the politicians who went along for the ride."
The Irish Sun has dropped its topless page three pin-ups, saying it "caters for a different audience" to the UK edition which is keeping the long-running feature.
The paper's editor Paul Clarkson said: "The Irish Sun shares the same qualities and personality that make the paper great everywhere: entertaining and engaging journalism, quality sports writing and showbiz coverage.
"But it also caters for a different audience in Ireland and we always strive to reflect our cultural differences here."
The new editor of The Sun has said that Page 3 is will remain in the paper.
David Dinsmore has come under increasing pressure recently from campaigners to stop printing topless pictures in the newspaper.
Speaking on LBC he said that a new exhibition at the British Museum was "far more explicit."
Mr Dinsmore said: "This is Japanese art - Spring Pictures as it's euphemistically called. It's given the editor of the Times the opportunity to put a naked Japanese lady on page 3, which as we know is a good way of selling newspapers."
When challenged on whether page 3 is safe he added: "It is, it is, yes I can tell you that.
"This stuff at the British Museum is far more explicit and raunchy."