The Metropolitan police has rowed back from its warning that journalists could face prosecution if they publish any further leaked diplomatic cables such as those that ran in the Mail on Sunday last weekend, precipitating the resignation of the British ambassador to the US, Kim Darroch.

In a statement released on Saturday afternoon, the Met assistant commissioner Neil Basu said the force “respects the rights of the media and has no intention of seeking to prevent editors from publishing stories in the public interest in a liberal democracy. The media hold an important role in scrutinising the actions of the state.”

“We are, however, a body charged with enforcing the law, and we have received legal advice that has caused us to start a criminal inquiry into the leak of these specific documents as a potential breach of the Official Secrets Act (OSA). The focus of the investigation is clearly on identifying who was responsible for the leak,” Basu added.

“However, we have also been told the publication of these specific documents, now knowing they may be a breach of the OSA, could also constitute a criminal offence and one that carries no public interest defence.

“We know these documents and potentially others remain in circulation. We have a duty to prevent as well as detect crime and the previous statement was intended to alert to the risk of breaching the OSA.”

On Friday, in a clear shot across the bows of newspapers planning to follow up last weekend’s revelations in the Mail on Sunday, Scotland Yard cautioned media organisations against running leaked government documents.

“I would advise all owners, editors and publishers of social and mainstream media not to publish leaked government documents that may already be in their possession,” the statement read, “or which may be offered to them, and to turn them over to the police or their rightful owner, Her Majesty’s government.”

However, throughout Saturday politicians and members of the media attacked the force’s heavy-handedness, including both of the Tory leadership candidates.

Boris Johnson said that stopping newspapers printing such documents would represent “an infringement on press freedom and have a chilling effect on public debate”.

His rival, Jeremy Hunt, tweeted that the leaks had “damaged UK/US relations and cost a loyal ambassador his job, so the person responsible must be held fully to account. But I defend to the hilt the right of the press to publish those leaks if they receive them and judge them to be in the public interest: that is their job.”

Q&A What did Sir Kim Darroch write about Trump in the cables? Show In the cables allegedly leaked to the Mail on Sunday, the UK’s outgoing ambassador to Washington, Sir Kim Darroch told his bosses in London that: He did not believe the Trump administration would “become substantially more normal; less dysfunctional; less unpredictable; less faction riven; less diplomatically clumsy and inept”.

Trump may have been indebted to “dodgy Russians”.

There were bitter divisions within the Trump White House, saying euphemistically that administration officials would get into “knife fights”.

The Trump presidency could “crash and burn” and that “we could be at the beginning of a downward spiral ... that leads to disgrace and downfall”.

The US president’s approach to global trade could wreck the system on which it depends.

Trump could attack Iran, and that he abandoned the Iran nuclear deal as an act of 'diplomatic vandalism' to spite Barack Obama.

The White House was split over the withdrawal, and lacked a "day-after" plan for what might come next.

Their Tory colleague Michael Fallon, the former defence secretary who is backing Johnson, had earlier said that anyone “receiving stolen material … should give it back to the rightful owner and should be aware of the huge damage done and potential greater damage by further breaches of the Official Secrets Act.”

The Labour leader, Jeremy Corbyn, said the leaks were “clearly a breach of confidence [and] information that should have been maintained as private. That has not happened and so the police have been involved and I think that is a normal process.”

He said: “Freedom of the press is vital, of course. There are rules around that and there are considerable protections for journalists who do reveal things and that, of course, is the right thing to do.”

Before the Met’s statement was released, George Osborne, the Evening Standard editor and former chancellor, tweeted: