• Video report by ITV News Political Correspondent Carl Dinnen

The campaigner who launched a legal challenge against Boris Johnson over his Brexit claims says the court battle is not about stopping the UK from leaving the EU.

In his first television interview, Marcus Ball exclusively told ITV News his primary objective is to "stop lying in politics", but admitted he doesn't know all the financial backers who've supported the crowdfunded private prosecution.

Dismissing claims it is a Trojan horse to stop Brexit, Mr Ball said the case, which was mounted in February, would never have passed through the court system ahead of March 29 - the date the UK should have left the EU.

He said: "There's absolutely no way way that our case - a case of this size and of this importance - could have been finished within the month" between it being launched and the UK's planned EU departure.

Mr Ball admits he is against the United Kingdom leaving the European Union, but says the "primary objective has always been to stop lying in politics".

He estimates around 12,000 people have contributed to the crowdfunding campaign for the case, raising more than £200,000.

He joked: "As far as I'm aware, we don't have any secret billionaires funding us."

The website used to raise the funds allows people to donate money anonymously. Mr Ball said: "The only way that I would ever be able to tell exactly who they were is if the judge ordered me and Crowdfunder to disclose the names of everybody involved."

He said he would not be aware if funding was coming from foreign state actors seeking to influence British politics - but says he is in control of the case and will not be influenced by anyone other than his legal team.

He said he had declined a financial offer to change a key facet of the case.

The private prosecution has been financed through crowdfunding. Credit: ITV News

Responding to press speculation, he added any funds taken as a salary from the crowdsourced money were given specifically to for that reason.

He told ITV News he is living on "approximately £24,000 a year" since he started the legal challenge whilst working hours would mean his earnings equate to "far less than the minimum wage".

He added: "This is not a way of cashing in, I'm doing this because I believe in it and it's important."

Tory leadership hopeful Boris Johnson has been called to court to answer to the allegation he misled the public over the now infamous £350 million given to the EU by the UK during the referendum campaign.

A date is set for Mr Johnson's High Court challenge against a court summons over allegations of misconduct in a public office.

Boris Johnson has been called to court over the case raised by Mr Ball. Credit: PA

The former foreign secretary's lawyers are expected to argue the summons was unlawful and the criminal proceedings against him should be dropped.

Mr Johnson's legal team previously told Westminster Magistrates' Court the MP denies acting dishonestly.

Mr Ball said he is "aware Mr Johnson's legal team are launching a judicial review, and we are contesting that".