Shadow foreign secretary Hilary Benn was cheered and applauded by MPs in the Commons after he appealed to Labour members to confront the "evil" posed by Islamic State by voting for airstrikes to be extended into Syria.
Speaking in the Commons on Wednesday night, Mr Benn said: "We must now confront this evil. It is now time for us to do our bit in Syria.
"And that is why I ask my colleagues to vote for this motion tonight."
After his speech there was a sustained period of applause from the Commons.
Earlier in his speech Mr Benn told MPs he accepted there were arguments against extending action.
He said: "I accept that there are legitimate arguments, and we have heard them in the debate, for not taking this form of action now and it is also clear that many members have wrestled and who knows in the time that is left may still be wrestling with what the right thing to do is.
"But I say the threat is now and there are rarely, if ever, perfect circumstances in which to deploy military forces."
Foreign Secretary Philip Hammond praised Mr Benn's "outstanding" speech, saying it would "go down as one of the truly great speeches made in this House of Commons".
Stella Creasy said the speech had persuaded her that "fascism must be defeated."
Several MPs including Lib Dem leader Tim Farron, Tory minister Claire Perry and anti-bombing Labour MP Shabana Mahmood also congratulated Mr Benn.
Shadow Chancellor John McDonnell acknowledged Mr Benn's "great" oratory but warned: "It reminded me of Tony Blair's speech taking us into the Iraq War.
"I am always anxious that the greatest oratory can lead us into the greatest mistakes.
"That is what it did in Iraq and I fear we made a mistake last night."
Labour said Mr Corbyn was still in control of the party but described the vote as “very worrying”.