MPs approve UK military intervention in Iraq against Islamic State (IS) by 524 to 43 votes
David Cameron told the Commons that IS poses a threat to the "streets of Britain" and the UK has a "duty" to confront it militarily
Motion states that IS is threat to UK directly, that government of Iraq has requested assistance and that authorisation does not extend to action in Syria
Lord Hannay of Chiswick, a crossbencher and former UK ambassador to the UN, says "the case for acting now is compelling" given the attorney general's legal advice and the invitation from the Iraqi government to take action.
Iraq's very survival is at stake, Sir Ming cautions, and says the UK has a degree of responsibility to act, as the 2003 invasion has been a "major contributor" to current circumstances.
Sir Ming Campbell - former leader of the Liberal Democrats - is now addressing the Commons. This is an entirely different set of circumstances from Iraq in 2003, he tells MPs, and notes that the UK would be responding to a request from the "lawful" Iraqi government. He insists there is a legal basis for UK participation in air strikes against Iraq.
Lord Alderdice, convenor of the Lib Dem leader in the Lords, opens by saying that the request for help from the Iraqi government and the "brutality" of Islamic State actions means that "we have little alternative but to render such assistance as we can".
Nick Robinson
Political editor
tweets:, external Debate on paper = UK military action v IS in Iraq. Commons will vote Yes. Debate in reality = should Syria be next? Mood of real anxiety
Mark D'Arcy
Parliamentary correspondent
First Lib Dem speech in either House - Lord Alderdice, now up in the Lords.
The Times' Sam Coates tweets, external: Peter Hain makes clear he believes strikes in Syria may be justified even if illegal. Taking harder stance than EM.
Former Conservative Cabinet minister Ken Clarke says the case for action in Syria as well as Iraq is "clear" - and that it is "artificial" to divide the two problems. He stresses that the UK "did not create extremists jihadists", but "we made things worse and we made it easier for them to spread through some of our interventions".
Labour MP Fiona Mactaggart tweets, external: colleague John Woodcock, who unlike me knows how to vote today, says failure to build effective Iraqi state following invasion creates duty to act now
Speakers in the House of Lords today are expected to include former ambassador to the UN, Lord Hannay of Chiswick (crossbench), the Archbishop of Canterbury, former Conservative Party leader Lord Howard and Labour's former home secretary Lord Reid.
Labour's Peter Hain follows, and sets out his support for the government's motion. He says he shares his party leadership's caution about extending action to Syria without UN backing, but adds that allowing IS to retreat "across an invisible border to them which they control into Syria to regroup is no answer".
Sir Richard Ottoway wraps up his speech but telling the House: "It is with a feeling of depression and trepidation that I will be supporting the government tonight."
Richard Benyon MP tweets, external: Really excellent speeches from Prime Minister and Leader of Opposition. Parliament at its best
Sir Richard says intervention is the "very least" the UK can be doing, as a world leader in the EU, Nato and the G8. But he laments that the motion does not propose action in Syria, noting that the country's border with Iraq has "virtually disappeared".
Addressing Mr Miliband's calls for a UN Security Council resolution before action in Syria could be taken, the Tory MP emphasises that Russia has indicated it would veto such a resolution - and tells the Labour leader it is incumbent on him to say what his position would then be.
Mark D'Arcy
Parliamentary correspondent
Lords told that debate will end at 16:30 BST if backbench speeches kept to four minutes - enabling their debate to influence Commons.
Dominic Casciani
Home affairs correspondent, BBC News
The PM repeatedly told MPs that the key issue for the UK is the threat that ISIL poses on our own streets. Security chiefs think that at least 500 people from Britain have gone to fight. As of June, there had been 69 arrests and some 15 cases have been going through the courts. Many of those who first went to fight said they would never come back - but security chiefs fear "blowback" - that some of these men will return radicalised and ready to strike the UK.
Sir Richard says the battle is one between "young and radical" militants versus the "slow democracies" of the West and the civilised world. But these democracies are our strength, he argues, as they give us a legitimacy that IS and similar rebel groups will never have, and that is what will ultimately undermine them.
A few procedure points: the first speaker in the Lords is leader of the House Baroness Stowell of Beeston, who is setting out the government's position as outlined earlier in the Commons by the prime minister. She will be followed by shadow deputy leader of the House Lord Hunt of Kings Heath, who will set out the Labour party's position.
That concludes the front bench speeches for now - opening the floor to backbench MPs. Speaker Bercow announces that 77 MPs are hoping to speak in the debate. As we mentioned earlier - there is a five-minute time-limit on speeches. The first of the backbench speeches comes from Sir Richard Ottaway, the Conservative chair of the Foreign Affairs Select Committee.
Conservative MP Bill Wiggin raises a point of order with the Speaker to complain about a TV camera crew in the chamber - which is filming for a BBC documentary.
He says they should be relocated, as they are obstructing MPs from getting in to the chamber. Speaker John Bercow does not agree.