False statements in political campaigns are “not new”, High Court judges who quashed a court summons for Boris Johnson have said.

The Conservative MP, who is tipped to become prime minister, was originally ordered to face charges of misconduct in public office over claims that the UK pays the EU £350m a week.

But the High Court overturned a summons issued by a district judge last month, after Mr Johnson’s lawyers argued the figure was a “political claim open to contradiction and debate”.

Laying out their reasons for the decision on Wednesday, Lady Justice Rafferty and Mr Justice Supperstone said: “The problem of false statements in the course of political campaigning is not new and has not been overlooked by parliament. For at least the last 120 or so years parliament has legislated to control certain false campaign statements which it considers an illegal practice.”

But the laws do not cover arguments used in political campaigns like the 2016 EU referendum, the judges found.

Opposing protesters flock to parliament on would be date of Brexit Show all 30 1 /30 Opposing protesters flock to parliament on would be date of Brexit Opposing protesters flock to parliament on would be date of Brexit Pro-Brexit leave the European Union supporters attend a rally in Parliament Square after the final leg of the "March to Leave" in London AP Opposing protesters flock to parliament on would be date of Brexit The protest march which started on March 16 in Sunderland, north east England, finished on what was the original date for Brexit to happen before the recent extension Reuters Opposing protesters flock to parliament on would be date of Brexit A Brexit supporter holds up a poster during a rally after the final leg of the "March to Leave" in London, Friday, March 29, 2019. Pro-Brexit demonstrators were gathering in central London on the day that Britain was originally scheduled to leave the European Union. (AP Photo/ Kirsty Wigglesworth) Kirsty Wigglesworth AP Opposing protesters flock to parliament on would be date of Brexit A pro-Brexit protester holds a sign next to a statue of Winston Churchill at the March to Leave demonstration in London, Britain March 29, 2019. REUTERS/Toby Melville TOBY MELVILLE Reuters Opposing protesters flock to parliament on would be date of Brexit Brexit demonstrators in Parliament Square in Westminster, London. PRESS ASSOCIATION Photo. Picture date: Friday March 29, 2019. See PA story POLITICS Brexit. Photo credit should read: Jonathan Brady/PA Wire Jonathan Brady PA Opposing protesters flock to parliament on would be date of Brexit Pro-Brexit protesters hold signs and wave flags at the March to Leave demonstration in London, Britain March 29, 2019. REUTERS/Toby Melville TOBY MELVILLE Reuters Opposing protesters flock to parliament on would be date of Brexit epa07471421 Pro-Brexit protesters gather outside of the Parliament for Nigel Farage's 'March to Leave' in London, Britain, 29 March 2019. MPs rejected Prime Minister's May EU withdrawal agreement earlier in the day. EPA/NEIL HALL NEIL HALL EPA Opposing protesters flock to parliament on would be date of Brexit A Brexit supporter sips a can of Stella in protests outside of the Houses of Parliament AFP/Getty Opposing protesters flock to parliament on would be date of Brexit Dedicated anti-Brexit campaigner Steve Bray and likewise pro-Brexit campaigner Joseph Afrane go head to head near the Houses of Parliament AFP/Getty Opposing protesters flock to parliament on would be date of Brexit A pro-Brexit marching band in Parliament Square Getty Opposing protesters flock to parliament on would be date of Brexit Remain supporters wave EU flags from a bus in Parliament Square PA Opposing protesters flock to parliament on would be date of Brexit A Brexit supporter shouts slogans outside parliament EPA Opposing protesters flock to parliament on would be date of Brexit A Brexit supporter protests outside parliament Reuters Opposing protesters flock to parliament on would be date of Brexit A Brexit supporter protests outside of the Houses of Parliament Getty Opposing protesters flock to parliament on would be date of Brexit Brexit supporters protest outside of the Houses of Parliament REUTERS Opposing protesters flock to parliament on would be date of Brexit A pro-Brexit flag is waved in Parliament Square AP Opposing protesters flock to parliament on would be date of Brexit The March to Leave nears the Houses of Parliament Reuters Opposing protesters flock to parliament on would be date of Brexit A Brexit protester holds a sign outside parliament EPA Opposing protesters flock to parliament on would be date of Brexit Brexit supporters carry the coffin of democracy AFP/Getty Opposing protesters flock to parliament on would be date of Brexit Brexit supporters march outside parliament AFP/Getty Opposing protesters flock to parliament on would be date of Brexit Brexit supporters take part in the March to Leave protest in London PA Opposing protesters flock to parliament on would be date of Brexit Brexit supporters protest outside parliament AFP/Getty Opposing protesters flock to parliament on would be date of Brexit A Brexit supporter holds a sign outside the Houses of Parliament Getty Opposing protesters flock to parliament on would be date of Brexit A man holds satirical paintings of politicians Reuters Opposing protesters flock to parliament on would be date of Brexit An pro-Brexit float on the March to Leave march in London Reuters Opposing protesters flock to parliament on would be date of Brexit Far-right activist Tommy Robinson addresses protesters outside the Houses of Parliament Getty Opposing protesters flock to parliament on would be date of Brexit A Brexit supporter outside the Houses of Parliament Reuters Opposing protesters flock to parliament on would be date of Brexit A Tommy Robinson supporter arrives at the Houses of Parliament Getty Opposing protesters flock to parliament on would be date of Brexit A jogger gestures rudely at a Brexit supporter outside of the Houses of Parliament AFP/Getty Opposing protesters flock to parliament on would be date of Brexit A Brexit supporter outside the Houses of Parliament PA

“There is no precedent for any office holder being prosecuted for misconduct in public office for wilfully making or endorsing a misleading statement in and for the purposes of political campaigning,” their ruling added.

It said that allegations that Mr Johnson knew Vote Leave’s £350m-a-week claim, which was emblazoned on the side of a bus, was false would not amount to neglect of duties or the abuse of state power.

A 2016 Electoral Commission report predicted that opposing sides of the Brexit debate would contest each other’s claims but said it was the “role of campaigners to debate the relative merits of their arguments”.

“Even official data can and will be presented by campaigners in a way that favours their argument – that is the nature of political campaigns,” the report added. “It will not always be possible to establish the truth about campaign claims in an independent truly objective sense.”

Adrian Darbishire QC, who represented Mr Johnson, had told the High Court it was “abundantly clear that this prosecution is motivated by a political objective and has been throughout”.

On 29 May, District Judge Margot Coleman had thrown out his argument that the case was a “vexatious” attempt to undermine the result of the 2016 referendum.

But the High Court judges said they could “detect no reasoning to support her conclusion”.

Their ruling said that 29-year-old Marcus Ball, who raised more than £300,000 through crowdfunding campaigns for the private prosecution, had deleted large parts of his social media history.

Boris Johnson says 'watermelon smiles' remark was 'wholly satirical'

The judges highlighted posts on Mr Ball’s 2016 crowdfunding website that discussed numerous legal options to “prevent Brexit”, and said Mr Ball had called himself “pro-Remain” and backed a second referendum in media interviews.

“The passage of time since 2016 was no answer to the claimant’s detailed submission that the political motive for the prosecution is apparent,” their ruling said.

“Though it is not necessary, we would also have quashed the decision [to summons Mr Johnson to court] on the basis that the finding that the prosecution was not vexatious was flawed.”

Mr Ball said he was considering whether launch an appeal against the High Court’s ruling.

He described himself as “very happy” after reading the full judgment, adding: “My legal team and I will carefully review it before making our decision as to what precisely we will do next.”