Boris Johnson to formally take charge as PM with promise to meet Brexit deadline

Boris Johnson is set to take 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 will lay 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 will formally invite 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 [Labour leader] 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 addresses her final Prime Minister's Questions in the House of Commons on Wednesday and is then expected to make 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.

As the face of hard Brexit in the ruling Conservative Party, Johnson has pledged to get Britain out of the European Union (EU) within the deadline of October 31 with or without a deal.

The prospect will prove divisive as the Opposition Labour Party and pro-EU Liberal Democrats have already voiced plans to bring down his government if he attempts a drastic no-deal exit from the EU.

Labour leader Jeremy Corbyn has demanded that Johnson call a General Election and promised to table a motion of no confidence in him "when it is appropriate to do so".

The MPs from within Johnson's own party remain vehemently opposed to a no-deal Brexit, with Chancellor Philip Hammond, justice secretary David Gauke and international development secretary Rory Stewart among some of the Cabinet members who have already declared their defiance by refusing to serve in his Cabinet.

Johnson is expected to spend his first few hours at No. 10 Downing Street finalising the top jobs in his Cabinet, with Indian-origin MP Priti Patel widely tipped to be back in the frontline after she had been forced to resign from May's Cabinet as international development secretary in 2017.

The 47-year-old ardent Brexiteer declined to "speculate" over Johnson's plans but said she was confident the new Prime Minister had plans for a "diverse" Cabinet, given his track record of deploying a diverse team as the Mayor of London.

"It is important that the Cabinet should represent modern Britain as well as a modern Conservative Party," said Patel, a prominent member of the "Back Boris" leadership campaign.

Fellow Brexiteer Rishi Sunak, the son-in-law of Infosys co-founder Narayana Murthy, and housing minister Alok Sharma are also in line for frontline jobs in what Indian-origin peer Lord Jitesh Gadhia has hailed as the most diverse Cabinet in British history.

"Boris Johnson will appoint the most ethnically diverse Cabinet in British history. This is a big moment and a bold statement by the incoming Prime Minister," said Gadhia.

Johnson, the UK's third Prime Minister since the June 2016 referendum in favour of Brexit, will face some of the same challenges as in the path of May, including a very slim parliamentary majority and a reliance on the support of the Democratic Unionist Party (DUP) of Northern Ireland in order to govern.

The DUP has been one of the central critics of the controversial Irish backstop a post-Brexit insurance policy against a hard border between EU member-country Ireland and UK territory Northern Ireland.

It has been rejected by Brexiteers as a way of keeping the UK tied to EU rules even after Brexit, ultimately resulting in the collapse of May's premiership.