Labour MPs rose to their feet to give John Bercow a standing ovation after he announced he would be standing down.
While a smattering of sacked Tories also rose, most of those on the government benches stayed sitting down.
An emotional Speaker held back tears as he heard tributes from across the House.
Mr Bercow said: "Thank you for the expressions of support from both sides of the house which are richly appreciated."
In an impassioned speech, he told MPs he would stand down as speaker on October 31 unless an election is called before then.
It means he will still be in the chair in case rebel MPs try and stop no deal until the last possible moment.
Addressing the Commons while his wife looked on from the gallery, Mr Bercow said: "At the 2017 election, I promised my wife and children that it would be my last.
"This is a pledge that I intend to keep. If the House votes tonight for an early general election, my tenure as Speaker and MP will end when this Parliament ends.
"If the House does not so vote, I have concluded that the least disruptive and most democratic course of action would be for me to stand down at the close of business on Thursday, October 31.
Mr Bercow continued: "Least disruptive because that date will fall shortly after the votes on the Queen's speech expected on October 21 and 22.
"The week or so after that may be quite lively, and it would be best to have an experienced figure in the chair for that short period.
"Most democratic because it will mean that a ballot is held when all members have some knowledge of the candidates.
"This is far preferable to a contest at the beginning of a parliament when new MPs will not be similarly informed and may find themselves vulnerable to undue institutional influence."
Mr Bercow has been a controversial figure and has been dogged by accusations of bullying an harassment which he strongly denies.
While he has clashed with the Tory governments - especially former Leader of the House Andrea Leadsom- Labour has welcomed his stewardship.
Veteran MP, Margaret Beckett said, after Bercow was accused of bullying Commons staff, that " Brexit trumps poor behaviour".
