The vote came directly after a speech from Hilary Benn, the UK Labour Party's shadow foreign secretary, which Conservative Foreign Secretary Philip Hammond called "one of the greatest speeches" in British House of Commons history.

In the speech, Benn broke with his party's leader, Jeremy Corbyn, and called for the UK to extend its airstrikes to Syria.

"We have a moral and practical duty to extend to Syria the acts we are now taking in Iraq," Benn told the Commons, addressing his party directly.

"We are here faced by fascists," he said of ISIS. "Not just their calculated brutality but their belief that they are superior to every single one of us in this Chamber tonight and all of the people that we represent. They hold us in contempt. They hold our values in contempt. They hold our belief in tolerance and decency in contempt."

"And what we know about fascists is that they need to be defeated and it is why, as we have heard tonight, socialists and trade unionists were just one part of the international brigade in the 1930s to fight against Franco," Benn continued.

"It's why this entire House stood up against Hitler and Mussolini. It's why our party has always stood up against the denial of human rights and for justice and my view, Mr. Speaker, is that 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 in favor of this motion tonight," he said.