(Bloomberg) -- British politicians of all stripes -- from Tory leadership contenders Boris Johnson and Jeremy Hunt to Labour Party leader Jeremy Corbyn -- defended freedom of the press after the Metropolitan Police said journalists could face prosecution if they published more leaked diplomatic cables.

Police have opened a criminal investigation into how messages from Kim Darroch, the U.K.’s now-former ambassador to the U.S., wound up in the Mail on Sunday last weekend. Further documents could potentially remain in circulation, the police said.

Fallout from the leaked information has stoked tensions -- already high because of Brexit -- within the U.K. government. Even before the Mail’s report on Darroch, which led to his resignation three days later, the government had been weakened by leaks. Gavin Williamson was fired as defence secretary in May because Prime Minister Theresa May blamed him for the leak of confidential documents related to Huawei Technologies’s involvement in Britain’s 5G communications network.

The controversy over Darroch’s cabled comments -- criticizing the Trump administration as “inept” and “dysfunctional” -- became a key element of the latest jousting between Johnson and Hunt for the Tory crown. Johnson declined to support the ambassador in a TV debate, prompting Hunt to say it showed Johnson wouldn’t face up to the U.S. president if he becomes premier.

Johnson, favored to beat Hunt to the premiership in this month’s vote, said the issues surrounding Darroch’s emails were embarrassing rather than a threat to national security. His opponent backed the police probe of the leak but also supported the right of the press to publish.

Opposition party leader Corbyn joined to support the media.

“Freedom of the press is vital, of course,” Corbyn said. “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.”

The political backlash prompted the police to moderate its message slightly. In a Friday statement, Assistant Commissioner Neil Basu advised all media not to publish leaked official documents and to hand them over to the police or back to the government, or face prosecution under the Official Secrets Act.

By Saturday, Basu said the police had “no intention of seeking to prevent editors from publishing stories in the public interest in a liberal democracy.”

“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.”

To contact the reporter on this story: James Ludden in New York at jludden@bloomberg.net

To contact the editors responsible for this story: Matthew G. Miller at mmiller144@bloomberg.net, Steve Geimann

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