The 46-year-old opposition lawmaker received 322 votes in the third round of voting in a secret ballot, against the 271 received by his rival and fellow Conservative Member of Parliament (MP), Sir George Young.

Bercow relied on support from the ruling centre-left Labour Party to win the post.

The Conservative MP promised to make a "clean break" with the past and bring parliament into line with the 21st century. Always the bookmaker's favorite to win the race to be Commons speaker, Bercow warned lawmakers ahead of the vote that parliament had to be reformed if it wanted to be taken seriously.

"Unless and until we can move the debate on from sleaze and second homes to the future of this House, we shall remain in deep trouble," Bercow said. "A legislature cannot be effective while suffering from public scorn."

After beating nine other candidates for the post, he feigned reluctance and, according to tradition, was dragged to the speaker's chair to take up his position in a job that is supposed to be politically neutral.

"We have faced quite the most testing of times, it has been a grueling experience, many members feel sore and very vulnerable but large sections of the public also feel angry and disappointment - we do have to reform," Bercow told parliament, referring to the fallout from the expenses scandal.

The governing Labour Party has largely borne the brunt of public outrage over MPs' lavish parliamentary expenses. Bercow's predecessor, Michael Martin, stepped down due to the affair, becoming the first speaker in 300 years to be forced from his post.

nrt/Reuters/AP

Editor: Nathan Witkop