Both Labour and the Liberal Democrats – which co-signed the historic 2013 cross-party agreement on press self-regulation – have now publicly demanded that David Cameron deliver on his promises.

Labour accuse him of ‘back-tracking’ on implementing the Leveson reforms while the Liberal Democrats say he seems to care more about media moguls than about those who suffer at the hands of the press.

The parties were responding to this week’s open letter to the Prime Minister from victims of press abuse, who expressed anger that he is breaking a string of promises to them on press reform.

Maria Eagle, Labour’s Shadow Culture Secretary, said: ‘It’s time David Cameron and his Culture Secretary, John Whittingdale, delivered on the Government’s clear promise to the British public, to Parliament and directly to the victims of phone hacking and fully implemented the cross-party agreement on Leveson’s recommendations.’

Liberal Democrat spokesman Lord Clement-Jones said: ‘The Prime Minister must reassure people immediately that he intends to implement the agreement; his silence so far is a strong cause for concern.’

The cross-party agreement sprang from a rare consensus that, because politicians must not play politics with press freedom, there would be a non-partisan approach to implementing the Leveson Inquiry recommendations. At the time, the Prime Minister not only stressed the importance of implementation, but he welcomed and praised this cross-party cooperation.*Maria Eagle called on Cameron to honour the agreement: ‘The Government must get on with commencing Section 40 of the Crime and Courts Act 2013 immediately and get on with facilitating the second part of the Leveson inquiry.

‘By pretending it is business as usual and backtracking on Leveson, the Tories are deliberately turning a blind eye to serious allegations of high-level corruption and collusion between the press, the police, politicians and the judiciary.’

Lord Clement-Jones said: ‘Cameron’s failure to uphold cross-party agreement on press regulation has left victims of press intrusion feeling like his loyalties lie more with media moguls than with the people who have had their privacy invaded.

‘The Liberal Democrats fought hard to secure this deal when we were in Government and we will continue fighting to make sure it is delivered.’-------*For example, on 18 March 2013, he said:‘Let me conclude by saying a word about the process by which the agreement has been reached and about the next steps. The royal charter agreed today has benefited hugely from hundreds of hours of detailed negotiations with representatives of victims, all main political parties and the press themselves, and has been further improved by the hours of discussions between the parties this weekend. I am grateful for the spirit of give and take on all sides. We stand here today with a cross-party agreement for a new system of press regulation that supports our great traditions of investigative journalism and free speech and protects the rights of the vulnerable and the innocent. If this system is implemented, the country should have confidence that the terrible suffering of innocent victims, such as the Dowlers, the McCanns and Christopher Jeffries, should never be repeated. My message to the press is now very clear: we have had the debate, now it is time to get on and make this system work.’