Boris Johnson, the former UK Foreign Secretary and an ardent critic of Theresa May's Brexit strategy, has confirmed he will run for leadership of the Conservative Party when the beleaguered Prime Minister announces her departure, CNN reports.

"Of course I'm going to go for it," he told a BBC news anchor at a business conference in Manchester, when asked if he would be a candidate.

May has said she will stand aside once Brexit has been delivered, but her Withdrawal Agreement with the European Union has been soundly rejected three times by Parliament.

The agreement will next be put to lawmakers at the beginning of June, and Conservative Party officials said on Thursday that May had agreed to set out the timetable for her departure after that vote.

Johnson, a former Mayor of London, has long held leadership ambitions. He has been an arch critic of May's Brexit approach -- although he ultimately voted in favor of her plan on the third occasion it was placed before lawmakers.

He is a favorite among grassroots Conservative members but has faced opposition in the past from a significant number of the party's MPs.

Widely expected to run for the Conservative leadership in the aftermath of the 2016 Brexit referendum, Johnson dramatically changed course after his former pro-Brexit ally Michael Gove announced his candidacy.

May eventually won that contest and appointed Johnson as her Foreign Secretary, but he resigned in July 2018, writing in his resignation letter that the Brexit "dream is dying, suffocated by needless self-doubt."

Johnson has supported leaving the EU without a deal, a scenario economists have warned would have a severe financial impact.

He has been a prominent figure in British politics for well over a decade, earning praise from some corners for his relaxed and bumbling persona, and criticism from others for a litany of gaffes, controversies and racially divisive comments.

He has called Africans "piccaninnies" and Papua New Guineans "cannibals," and once referred to Hillary Clinton as a "sadistic nurse in a mental hospital." Johnson also wrote last year that Muslim women wearing burqas resemble "letter boxes."

An MP since 2001, Johnson will face stiff opposition in what is anticipated to be a crowded field of candidates. The winner will not only take control of the Conservative Party, but also become prime minister and take center stage in the chaotic and fractured Brexit process.

Britain is currently scheduled to leave the European Union on October 31, having twice delayed its departure.