1.30pm: Watch highlights of the exchanges.

Highlights, not verbatim:

12.26pm: Great question from Michael Spicer: Why are there always so many strikes at the end of a Labour government?

12.23pm: In response to a question from Labour’s backbenches Gordon Brown says that the Conservatives are taking risks with the fight against crime and against terrorism by questioning the value of the DNA database and of CCTV.

12.15pm: Nick Clegg urges the PM to enact a windfall tax on the energy companies so that poorer households can be given better insulation and smart meters.  Brown says that the Government is already doing much to help poorer families with their energy bills.

12.12pm: Cameron calls for leadership from Brown but jokes that there is more spine in jellyfish than on Labour’s frontbench.  Brown quotes Ken Clarke’s view that a referendum would be "crackpot", "dotty" and "absurd".  He urges David Cameron to lead his party away from the Euroscepticism of the Conservative backbenches.

Brownatpmqs12.10pm: The Irish people have spoken.  They’ve said "no" says David Cameron.  What part of "no" doesn’t he understand?  Brown responds by reminding the House of John Major’s words when he urged continued ratification of Maastricht after the Danes had said "no".

12.09pm: Wouldn’t it "ridiculous" and "high-handed" Cameron continues, to ask the Irish to vote twice when the people of Britain haven’t had an opportunity to vote once?  Have the courage to declare it dead, urges the Tory leader.

12.07pm: Rapid change of tone when
Cameron invites Brown to declare the Lisbon Treaty "dead".  We must
have respect for the Irish, says the PM, but the Irish have not asked
us to delay our own ratification process.

12.05pm: David Cameron asks what progress has been made in creating one central command in Afghanistan.

12.04pm: The PM says that the Taliban
has been defeated as an army and are now fighting as an insurgency,
using weapons like suicide and roadside bombs.

12.02pm: David Cameron, following
Gordon Brown begins by paying tribute to the fallen in Afghanistan. He
says that the Afghan fight is a vital fight against terrorism that we
must win. It is about our security.