Controversial measures to saddle newspapers with the cost of legal disputes regardless of fault are "wrong in principle" and could play into the hands of ambulance-chasing lawyers, the head of a Parliamentary committee has warned.
Damian Collins, chairman of the culture, media and sport committee, said the proposals should not be implemented as they risk harming freedom of the press - and thus democracy - while filling solicitors' coffers.
The Conservative MP said that while press regulation is an important issue, the "greatest threat" to the media's credibility comes from rise of "fake news" on social media and elsewhere, rather than from newspapers.
He used an article in the Daily Telegraph to speak out against the activation of Section 40 of the Crime and Courts Act, before a Government consultation on the issue ends on Tuesday.
Should the clause be introduced, judges in libel and privacy cases would have the power to order publications to pay a plaintiff's legal costs, win or lose.
"It is hard to think of any other area of law where such a provision would be allowed," Mr Collins said.
"Some have said that the risk of heavy costs being awarded against the newspapers is not as great as some fear. But I believe it is wrong in principle, and once established could create a new industry of ambulance-chasing lawyers encouraging people to hire them on no-win, no-fee terms to take up complaints against the press.
"These lawyers could set high fees and know that there would be a good chance of getting paid even if they lost the case."
Mr Collins said the ability of the press to hold those in power to account is "one of the cornerstones of our democracy" and warned that the laws would have a chilling effect.
"The consequence would be to drive many newspapers out of business and to threaten the kind of investigative journalism that we so greatly value. Editors would understandably be concerned about the financial risk of causing embarrassment, even when they have a duty to report the truth," he said.
Section 40 forms part of a range of reforms proposed by Sir Brian Leveson following his inquiry into the culture and practices of the press in the wake of the phone hacking scandal.
Any newspapers that do not sign up to a recognised regulator would be vulnerable to the costs provision, which has been enacted by Parliament but requires the approval of the Culture Secretary, Karen Bradley.
She has said that she wants to maintain a free press while giving victims of intrusion access to "cheap justice".
However the law is seen by some as a blunt instrument designed to have newspapers to sign up to a regulator backed by royal charter, which MPs have the power to change.
Following the publication of Sir Brian's report a new regulator was created, the Independent Press Standards Organisation (Ipso), which has the power to adjudicate against newspapers and issue fines of up to £1 million.
Mr Collins said the press had made "substantial progress" in reforming how it governs itself. However he said the public needs to be made more aware of the existence of Ipso and the watchdog should roll out a low-cost means of arbitration.
Four years on from the Leveson report, the growing number of "fake news" reports online that spread misinformation and propaganda should be the focus for media monitors, the MP said.
"Press regulation is an important issue. But the greatest threat to the credibility of the media no longer emanates from newspapers. Instead it comes via the internet, where 'fake news' spreads without regulation through social media platforms and numerous other channels.
"That should be a greater concern for us now."