I spent many years as a reporter and editor at some of the country’s best newspapers, at the Manchester Evening News and Guardian, at the Northern Echo, the Sunday Times and the Times. I have watched with dismay as unethical and even illegal activities have polluted parts of the press to the extent that trust in the British press as a whole is the lowest in Europe. That’s unfair to those titles and individuals who hold to the highest public values, and is particularly alarming in the era of “fake news” that holds truth a hostage.

The decline can be resisted in Parliament’s vote today if MPs will back Leveson amendments to the Data Protection Bill.

The national newspapers, and their allies in the huge local media corporations, say these amendments threaten press freedom. Not so, if we are talking about the legitimate freedom to investigate wrongdoing and hold power to account. In the seventies I assailed the legal restrictions of the “half free” press, most notably in government and the legal system holding thalidomide families hostage through a decade of cruel and unfair litigation. Parliament freed the British press - after we won a famous victory in the European Court of Human Rights. It is very sad to see portions of the British press on the wrong side of the argument now

I gave evidence to Leveson, as I had done to Royal Commissions in the past. I followed the Leveson process closely. In the Cudlipp lecture after its publication I voiced some reservations about proposals, but I criticised press reporting that distorted Leveson.I am a patron of the only Leveson-standard regulator, IMPRESS, which has no responsibility for what I say here. What I can say without hesitation is that the measures in these amendments protect and enhance the freedom of journalists to do their job. They will close not a single newspaper nor chill a single public interest story.

The big newspaper groups assert that the Leveson process is about the past and not the future, but that is unhistorical and misleading – of course, for good reason. Leveson Part 2 would look into past wrongdoing, as most public inquiries do. But the cross-party amendment laid by Ed Miliband and Ken Clarke would also tackle fake news and manipulation of personal data on social media. I am with the big nationals and locals in supporting the Press Gazette campaign against the Facebook-Google duopoly whose greed is responsible for closing prime local news sources. .

Sir Brian Leveson himself says he ‘fundamentally disagrees’ with the Government’s decision to shut the inquiry before it has finished its work. I believe it’s unprecedented for the government to ignore the opinion of a senior judge – and a distinguished one - chairing a public inquiry. I cannot imagine the press supporting a decision prematurely to shut down a public inquiry into the harm inflicted by any other industry. (Alas there never was a public inquiry into thalidomide killing hundreds of babies).

The amendment that should be supported introduces a form of the “section 40” costs-shifting incentive . It is needed to protect independently regulated journalism from libel bullies, and to give access to justice to those people who can’t afford to take the unregulated newspapers through the courts. The charge that these amendments will harm local newspapers is wrong. Local newspapers will not be part of Leveson Part 2 and the Section 40 amendment exempts all local newspapers other than those whose owners turnover more than £100m per year.

As the vote approaches, some last-minute promises have been made.

I urge MPs to see them for what they are, the kind wheeled up over many decades to defend the indefensible. This is “the past” of hacking and shameful intrusion and a rejection of corrections proportional to the original offence. MPs would do well to recall what preceded Leveson 1 and not be party to the plot to abandon Leveson 2.

The amendments have been misrepresented by the usual suspects as party political manoeuvering when in fact they are genuine cross-party amendments which many Conservatives support. Supporters of these amendments are being true to the pledge sincerely made by a Conservative Prime Minister and endorsed across all parties by MPs with a conscience.

Listen not to the betrayers of those promises. Listen to Christopher Jefferies, to the McCanns and to all the other victims of shocking press abuse. It would be destructive of public trust if the vote turns out to be yet another failure of politicians to keep their promises. Today'ss vote is a chance to fix that.

Sir Harold Evans was editor of the Sunday Times 1967-81 and author of Good Times, Bad Times (fifth edition).