British politician Boris Johnson has won a challenge against a UK court summons over claims he misled the public during the Brexit campaign. The former foreign minister, who is the frontrunner to replace Theresa May as Britain's prime minister, had challenged a lawsuit on Friday accusing him of knowingly lying during the Brexit referendum campaign over claims that Britain would be £350m a week better off outside the EU. After hearing the evidence judges threw the case out. Mr Justice Supperstone said: "We are quashing the decision of the district judge to issue the summonses." Lawyers for Mr Johnson, who leads a crowded field of contenders vying to be Conservative Party leader after Mrs May formally resigned on Friday, claimed in court that the private prosecution was "politically motivated and vexatious". The MP, who was not present, had asked London's High Court to throw out a judge's decision last month to allow a summons ordering him to appear in court over allegations of misconduct in public office. His lawyers argued the lower court's ruling had "erred in law" and that the attempt to prosecute the ex-London mayor was political. "The only rational conclusion which could be reached was that the prosecution was politically motivated and, therefore, vexatious," Adrian Darbishire told two High Court judges hearing the challenge. After hearing the evidence in a judicial review the judges threw out the case. The case, brought by businessman Marcus Ball in a crowd-funded initiative, concerns Mr Johnson's claim that Britain sends £350 million a week to the European Union. While this was Britain's gross contribution, the net figure accounts for a budget rebate from the EU as well as payments to Britain's public sector from the EU budget, and is substantially less. The official Leave campaign emblazoned the controversial figure on the side of its touring bus during the 2016 EU referendum, while Johnson and other Brexiteers repeatedly trumpeted it campaigning. Mr Ball, 29, who has crowdfunded more than £300,000 through an online campaign to bring the case, told reporters ahead of the hearing he believed in "the merits of it". In a written decision on May 29, district judge Margot Coleman agreed, ruling she was satisfied there was a proper case to issue a summons -- prompting Friday's legal challenge. Mr Johnson launched his campaign to succeed May as Conservative leader on Monday. She steps down on Friday and formally triggers the race for a successor, but will remain prime minister until a new leader is chosen, likely in late July.