Boris Johnson has been elected as the new Prime Minister of the United Kingdom, his party announced on Tuesday, as the Tory members chose Johnson over Jeremy Hunt as Theresa May’s successor in Number 10.

Johnson, the former foreign secretary, secured 92,153 votes against 46,656 of his rival Jeremy Hunt in the battle for 10 Downing Street, which was triggered last month when a Brexit-battered Theresa May announced her resignation amid a mounting rebellion from within the party.

Conservative Party's over 160,000 members up and down the UK filed in their postal votes to decide between him and the current foreign secretary, Jeremy Hunt.

Johnson had been the front-runner throughout the contest.

Addressing the Tory party members at the Queen Elizabeth II Centre in London, near the Houses of Parliament, soon after the results were declared, Johnson, 55, said: "No one person or party has the monopoly of wisdom. Time and again it is to us [Conservative Party] that people have turned.

"At this pivotal point in history... I know that we will do it. The mantra is deliver Brexit, unite the country and defeat (Labour leader) Jeremy Corbyn.

"I will work flat out to repay your confidence. The work begins now."

The co-chair of the Tory party's 1922 Committee Cheryl Gillan MP opened the envelope to declare that Johnson won 92,153 votes compared to 46,656 polled for Hunt by a voting base of 159,320 Tory membership, with 509 rejected ballots. The poll turnout was pegged at 87.4 per cent, with Boris Johnson racing ahead with a vote of nearly two to one.

In terms of timeline, May will carry on as caretaker PM for a few days still as she is set to address her final Prime Minister's Questions session in the House of Commons on Wednesday after which she will head to Buckingham Palace to formally offer her resignation to Queen Elizabeth II.

The 93-year-old monarch will then meet the newly-elected Conservative Party leader and invite him to form a new government.

The new PM then traditionally makes a statement on the steps of 10 Downing Street before taking official charge before Parliament's summer recess is set to kick off from Friday until early September.

In one of final major prime ministerial acts, May is chairing the government's emergency Cobra meeting on Monday after a British-flagged tanker was seized by Iran in the Gulf last week.

She will receive updates from ministers and officials on the crisis since the vessel and its crew, including Indian nationals, was seized. It will be one of the first big international issue to address for any new PM as well.

With just hours to go before the vote closes, Johnson used his weekly newspaper column in the 'Daily Telegraph' to compare the Brexit negotiations and meeting the October 31 deadline for Britain to leave the European Union (EU) with the same "can-do spirit" behind putting a man on the moon 50 years ago.

He called for optimism in the approach to resolving the controversial Irish backstop issue, the controversial insurance policy insisted upon by the EU but seen as a means of keeping the UK tied to European rules even after Brexit.

The conundrum had resulted in May losing repeated parliamentary votes over her Brexit agreement, ultimately leading to her forced departure as British prime minister.

(With inputs from PTI)