Boris Johnson, a top contender to become Britain's next prime minister, will be summoned to court to answer questions about allegations he knowingly lied during while campaigning for Brexit, a judge said on Wednesday.

District Judge Margot Coleman said the former foreign minister will be questioned about possible misconduct in public office.

Read more: Who is Boris Johnson, Brexit champion and wannabe British PM?  

An individual pursuing private prosecution claims Johnson intentionally lied during the campaign for Brexit by claiming the UK sends £350 million ($440 million, €400 million) a week to the European Union.

This was a core claim of the official campaign for leaving the EU, "Vote Leave," with the message famously plastered across the group's campaign bus. The claim went on to say "Let's fund our NHS instead," in reference to the taxpayer-funded National Health Service. 

Allegations against Johnson 'unproven'

Johnson was by no means the only politician to repeatedly use the figure on the campaign trail, though he may have been the best known among them.

A large portion of UK contributions to the EU budget end up being reinvested in Britain, something the campaign neglected to mention.

The judge said the allegations against Johnson were "unproven," but that it was proper to issue a summons.

Johnson is a front-runner to lead the Conservative Party and become prime minister after Theresa May announced this month she would step down.

cw/msh (AFP, AP, Reuters)

Every evening, DW sends out a selection of the day's news and features. Sign up here.