Indian-origin Rishi Sunak, who will take over as Britain's prime minister from Liz Truss, on Monday promised stability and unity as his priority.

The former chancellor, who won Tory leadership contest on Monday, is poised to walk through the door of 10 Downing Street in London after an audience with King Charles III in Buckingham Palace, which is likely to be on Tuesday. Besides being the first Hindu Prime Minister of Indian heritage, Sunak is also the youngest for around 200 years at 42 years.

In his first address as Tory leader soon after the result was declared, Sunak said his priority would be to bring the country together and said he was "humbled and honoured" to get the greatest privilege of his life to give back to the country I owe so much .

"The UK is a great country, but there is no doubt we face a profound economic challenge," said Sunak from the Conservative Party headquarters near Parliament in London.

"We now need stability and unity and I will make it my utmost priority to bring our party and our country together; because that is the only way we will overcome the challenges we face and build a better, more prosperous future for our children and our grandchildren," he said.

"I pledge that I will serve you with integrity and humility and I will work day in day out to deliver for the British people," he said.

The former finance minister was comfortably in the lead, having secured the public backing of over half the 357 Tory MPs - way above the 100 minimum required to make the shortlist.

In time for the 2 p.m. local time Monday deadline, Sir Graham Brady, chair of the influential 1922 Committee of backbench MPs, announced in the Parliament complex that he had received only one "valid" nomination and therefore Sunak is the winner of the leadership contest.

I am asking you for the opportunity to help fix our problems, said Sunak, in his latest campaign pitch, with reference to the economic turmoil he is inheriting following Truss' disastrous tax-cutting mini-budget last month.

Sunak was runner-up in the last leadership race, securing the highest backing from MPs but losing out to Liz Truss after the vote went to Tory members.

The outgoing Prime Minister won on a mandate to slash taxes to spark economic growth, but she was forced to U-turn on almost all of her economic policies after her mini-budget sent the markets into financial turmoil and the Pound Sterling crashing.

Last week, she dramatically resigned and triggered another Tory leadership race, this time expedited by the 1922 Committee given the urgency of the economic climate.

Sunak had famously challenged Truss' plans as "fairy-tale economics", and his supporters repeatedly pointed out how he had got the big calls right and was therefore the right candidate to restore economic credibility.

PTI