Boris Johnson, then Britain’s foreign secretary, arrives for a cabinet meeting at 10 Downing Street in London in October 2017. (Alastair Grant/AP)

Boris Johnson, the front-runner in the contest to become the next British prime minister, was summoned Wednesday to appear in court over allegations that he lied during the 2016 campaign for Brexit.

Johnson has been accused of misconduct in a public office for claiming that Britain sends 350 million pounds (about $440 million) to the European Union every week.

“I accept that the public offices held by Mr. Johnson provide status, but with that status comes influence and authority,” District Judge Margot Coleman said in a statement. She did not make any factual findings but determined there was sufficient evidence to send the case to trial.

The ruling comes while jockeying is underway to replace Prime Minister Theresa May, who announced last week she would resign as Conservative Party leader on June 7 and make way for a new prime minister this summer. Johnson is one of 11 Conservative lawmakers who have declared their candidacy. The new leader is expected to be announced in July.

Johnson, who was a popular mayor of London when the Brexit campaign got going, galvanized the Leave campaign with his support. He famously posed beside the Vote Leave campaign bus, plastered with the slogan: “We send the E.U. £350 million a week. Let’s fund our NHS instead.”

Michael Gove, another contender for prime minister, embraced the figure as well, saying in an April 2016 speech: “If we left the E.U., we would take back control over 19 billion pounds which we currently hand over every year — about 350 million pounds each and every week.”

Johnson later upped his estimate, telling the Guardian last year: “There was an error on the side of the bus. We grossly underestimated the sum over which we would be able to take back control.”

The actual net sum Britain pays into the E.U. varies from year to year, but independent fact-checkers put the weekly figure at closer to 280 million pounds (about $350 million). UK Statistics Authority, a watchdog, has previously reprimanded Johnson for a “clear misuse of official statistics.”

Marcus Ball, an activist who crowdfunded nearly $300,000 to pay for the private prosecution, claimed Johnson “repeatedly lied and misled the British public as to the cost of E.U. membership,” according to court documents.

“Lying on a national and international platform undermines public confidence in politics, undermines the integrity of public referendums and brings both public offices held by the (proposed) defendant into disrepute,” Ball said, in the court document.

A statement made on behalf of Johnson, outlined in court documents, claimed the prosecution to be a political “stunt.”

“Its true purpose is not that it should succeed, but that it should be made at all. And made with as much public fanfare as the prosecution can engender,” it read.

A number of Conservative politicians raised concerns about the case’s implications for free speech. Among them was Gove, who tweeted: “Contending opinions and vigorous argument are the essence of democracy. We should trust the public to decide on the merits of a political case. We should not try to criminalise free speech.”

Johnson will first be summoned to a preliminary hearing — likely to take place in three to four weeks. A full jury trial, if it went ahead, wouldn’t be expected for at least six months.

Misconduct in public office carries a maximum penalty of life in prison.

This is not the first time Johnson has been accused of playing fast and loose with the truth.

He was fired from a job with the Times newspaper for allegedly fabricating a quote.

Later, as Brussels correspondent for the Daily Telegraph, he was accused of promoting euroskeptic myths, such as the notion that the E.U. wanted to impose rules about straight bananas.

Last month, the Telegraph was forced to correct one of Johnson’s weekly columns, after he falsely claimed polls showed a “no-deal” Brexit was the most popular option “by some margin” with the British public. In its correction, the paper said: “In fact, no poll clearly showed that a no deal Brexit was more popular than the other options.”