London: British Prime Minister Boris Johnson on Thursday appointed Indian-origin politician Rishi Sunak as the new finance minister in a Cabinet reshuffle.

Sunak, the son-in-law of Infosys Co-founder Narayana Murthy, will join Home secretary Priti Patel on the top government bench as UK Chancellor of the Exchequer.

The existing British finance minister Sajid Javid had resigned on Thursday, a surprise move that underlined Prime Minister Boris Johnson's desire to tighten his grip on government by jettisoning a minister who refused to toe the line.

Johnson, who had wanted to minimise any disruption from the cabinet reshuffle, quickly appointed Javid's deputy Rishi Sunak, a loyal supporter of the prime minister who has often been put in front of the cameras to sell government policy.

Johnson's team had carefully choreographed the reshuffle, presenting it as an opportunity to foster new talent, particularly among women, while also rewarding loyal supporters to deliver his vision for Britain beyond Brexit.

But the finance minister's resignation - which some commentators said might have been sought by Johnson's team - due to a dispute over Javid's advisers added to the picture that the prime minister will not tolerate dissent in his government.

His sacking of Northern Ireland minister Julian Smith, who only a month ago had helped broker the restoration of a government in the British province, prompted criticism from politicians north and south of the border with Ireland.

Smith, who had been in charge of parliamentary discipline for Johnson's predecessor, Theresa May, was the first minister to lose his job in the reshuffle. He was joined by business minister Andrea Leadsom and environment minister Theresa Villiers.

Ultra-loyal Alok Sharma, a former minister for international development, was appointed as the new minister for business and also the head of the COP26 climate change summit, when world leaders will travel to Scotland in November.

But it was Javid's move which shook up the 'business as usual' look that Johnson had wanted to portray.

Johnson's aides had previously played down suggestions, based on Johnson's senior adviser Dominic Cummings' well-publicised desire to see a radical reorganisation of government, that there would be major changes.

It was clear that loyalty mattered to Johnson to be able to deliver his agenda and meet the promises he made in the run-up to the December 12 election, in which he won a large majority.

(With inputs from PTI and Reuters.)