Former foreign minister Boris Johnson is the frontrunner to replace Theresa May as Britain's PM. (File)

Judges at London's High Court on Friday threw out an attempt to prosecute Boris Johnson, the front-runner to succeed Theresa May as prime minister, for allegedly lying about Brexit.

Last month, a judge said Johnson must appear in court over allegations he lied about Brexit by claiming during the 2016 rerferendum that Britain would be 350 million pounds a week better off outside the EU.

But judges overturned that decision at a judicial review hearing.