Boris Johnson becomes Britain's new Prime Minister

Boris Johnson formally took charge as Britain's new Prime Minister on Wednesday after his landslide victory in the Conservative Party leadership contest, following which he promised to "get Brexit done" by the October 31 deadline.

The 55-year-old former foreign secretary and London Mayor laid out his vision as Prime Minister in his first speech on the steps of Downing Street after an audience with Queen Elizabeth II at Buckingham Palace, during which the monarch formally invited him to form a government after accepting Theresa May's resignation.

"We are going to energise the country. We are going to get Brexit done on October 31 and take advantage of all the opportunities it will bring with a new spirit of can do," said Johnson, soon after being confirmed as the new Conservative Party leader and Prime Minister-elect on Tuesday.

"The mantra is deliver Brexit, unite the country and defeat Jeremy Corbyn," he added.

May, who was forced to resign amid a mounting rebellion from within her party over her Brexit strategy that failed to clear the Parliament votes threshold three times, has been functioning as a caretaker Prime Minister during the course of the Tory leadership.

She addressed her final Prime Minister's Questions in the House of Commons on Wednesday and then made a farewell speech on the steps of Downing Street before being driven to Buckingham Palace to formally offer her resignation to the Queen.

It is during this meeting that May is set to indicate to the 93-year-old monarch who commands the requisite support to form the next government, following which Johnson will be driven to the palace for his private audience with the Queen.