John Bercow, the Conservative Member of Parliament (MP), starts work as Speaker of the House of Commons amid signs of some Conservative opposition, Xinhua reported.
Bercow, who as the Daily Telegraph said "controversially won the contest to be the next Speaker of the House of Commons," got 322 votes to fellow Tory MP Sir George Young's 271 in the third and final round of secret voting.
Bercow will be in the chair for business in the Commons from 1430 BST Tuesday with his first challenge being to establish his authority over the House, amid the belief that some Conservative MPs are hoping to be able to mount a challenge to unseat him after the next election.
The new Speaker "will be under pressure to deliver on his promises and help put in place new procedures and systems to restore public trust in Parliament," the British Broadcasting Corporation said in its report.
Bercow is "unpopular with large swathes of the Conservative Party after undergoing a political journey from right-wing Thatcherite to outspoken social liberal rumored to have been close to defecting to Labour," the report said.
He won the support of many Labour MPs, who are convinced he will stand up to Conservative leader David Cameron, but there was a marked lack of applause from the Tory benches, the report said.
The Buckingham MP beat nine other candidates, including Labour's Margaret Beckett and Tory veteran Ann Widdecombe, to be named 157th Speaker, replacing Michael Martin who quit after nine years amid the furore over MPs' expenses.
On winning the ballot, Bercow said that MPs felt "very sore and very vulnerable" in the wake of the expenses scandal and added "large sections of the public were also angry and disappointed."
He said that "we do have to reform but I just want to say that I continue to believe that the vast majority of members of this House are upright, decent, honorable people who have come into politics, not to feather their nests, but because they have heeded the call of public service."