John Bercow has announced he will step down as Commons Speaker by October 31.

Speaking on Monday, Bercow said if there was a snap election before that date he would not stand again as an MP.

“At the 2017 election, I promised my wife and children that it would be my last,” he said in an emotional speech in the Commons.

Bercow said in his time in office he had sough to be the “backbenchers’ backstop” and help MPs stand up to the executive.

In a break with convention, the Conservatives planned to field a candidate against Bercow in his Buckingham seat.

The Speaker is an MP who stands in general elections but is usually unopposed by the major political parties.

Jeremy Corbyn praised Bercow for being a “superb” Speaker. “Our democracy is the stronger for your being the Speaker,” he said.

But Bercow had angered the government by allowing MPs to seize control of the parliamentary agenda to block a no-deal Brexit.

Andrea Leadsom, the business secretary, said on Sunday he had not “just bent the rules, he has broken them”.

“Give us back an impartial Speaker,” she wrote in the Mail on Sunday.

Leadsom served as Leader of the Commons for almost two years and has a long-running feud with Bercow.

In May last year the Speaker was alleged to have labelled Leadsom a “stupid woman”, as well as calling her “f****** useless”.

Among the names in the frame to succeed Bercow in the chair are former Labour deputy leader Harriet Harman and the current deputy Speaker, Lindsay Hoyle.