By Ian Dunt">
MPs have voted overwhelmingly to back military action in Libya, even as poll figures emerge showing the conflict is unpopular with the public.
The government won the vote by 557 to 13, although many MPs voiced their concerns and anxieties about the decision.
Meanwhile, a ComRes poll for ITV news showed 49% of people think military action in Libya is an unnecessary risk.
Only one in three (35%) thought it was right for the UK to take military action against Colonel Gaddafi's forces in Libya.
The vote came as a reminder to David Cameron of the political gamble he is taking, after the prime minister spent hours in the Commons Chamber listening to backbench MPs' concerns and trying to persuade parliament of the case for action.
"Gaddafi has had every conceivable opportunity to stop massacring his own people," he told the Commons.
"The time for red lines, threats and last chances is over. Tough action is needed now to ensure that people in Libya can live their lives without fear.
"There are difficulties and there are dangers ahead, but we already know beyond any doubt that we have succeeded in chasing Gaddafi's planes out the sky, we have saved the lives of many Libyans and we have helped to prevent the destruction of a great and historic city," he added.
Considerable doubts about coalition tactics, the parameters of the UN resolution and the lack of an exit strategy were expressed by MPs, as they have been by the governments of other countries.
Mr Cameron told the Commons that a no-fly zone was now effectively in place, after attacks "neutralised" Libya's air defence systems.
He warned that the international community may have to take "quite tough steps" to prevent attacks on civilians, including fighting off Libyan tanks if they try to enter the rebel stronghold of Benghazi.
'The shadow of history'
Labour leader Ed Miliband offered the prime minister his full support, saying the mission was a chance to show Britain's "humanity and solidarity".
"Today's debate is conducted in the shadow of history," he told a packed Commons Chamber.
"It is also conducted for me in the shadow of my family's history - two Jewish parents, whose lives were changed forever by the darkness of the Holocaust, yet who found security in Britain.
"This is the story of the hope offered by Britain to my family. That is why I'll be voting for this motion tonight."
The Labour leader faced critical questions from a handful of his own backbenchers. Some said the mission could be seen as hypocritical given the lack of action in Yemen and Bahrain, where embattled regimes have been accused of brutal human rights abuses against pro-democracy campaigners.
"In the world we live in, the action we take depends on a combination of principle and pragmatism," Mr Miliband added.
"That is not perfect. But an imperfect world order is not an excuse for inaction."
In the lead up to the vote, Arab League secretary-general Amr Moussa's outspoken attack over alleged civilian casualties raised concerns in Westminster about the extent of international support for the mission.
The prime minister's spokesman said David Cameron had spoken to Mr Moussa yesterday and that the two men were "on the same page" about protecting Libyan people and avoiding Libyan casualties.
Last night, at British jets returned to base due to concerns over possible civilian casualties, the Ministry of Defence (MoD) said.
"After the Tornadoes had taken off we learned there were some civilians in the area," said major general John Lorimer.
"We called off the attack. This clearly demonstrates we take all measures possible to reduce the chances of harming Libyan civilians."
But that was not enough to quell concerns from some countries. Both Russia and India have criticised the UN resolution.
"The resolution is defective and flawed," Russian president Vladimir Putin told workers at a Russian ballistic missile factory.
"It allows everything. It resembles medieval calls for crusades."
In a further bid to avoid any comparisons with Iraq, Downing Street published a short note summarising the attorney general's legal position, although it did not release his full legal advice to Cabinet.
The note cited Chapter VII of the UN Charter, which concerns action in response to threats to the peace, breaches of the peace and acts of aggression.
Mr Cameron also warned fighters loyal to Colonel Gaddafi that they might face an international criminal court after the conflict.
"Now is the time to put down your weapons, walk away from your tanks and stop obeying orders from this regime," the prime minister added.
Iraq continued to cast a long shadow over the thoughts of many experts, who warned that there was no discernable exit strategy.
Rear Admiral Chris Parry, former director-general in the UK defence ministry, told the BBC World Service: "You have to enter these things with some clear idea of what it is you want. I'm not at all sure we have a clear vision of what that is to be.
"We really do have to get to grips with what happens afterwards. If we don't, the military campaign will lose momentum, it will lack coherence and we'll lose broader political support within the Islamic world."
Sir Andrew Green, Britain's former ambassador to Saudi Arabia, said: "This has not been thought through, has it? That's my concern.
"If the aim is to remove Gaddafi, you're not going to remove him from 25,000 feet. So I think we're much more likely to get a stalemate than get dragged into a civil war.
"Yet again, we've attacked an Arab and Muslim country, with no clear plan and no exit strategy. It's simply amazing."
This afternoon, around 200 people gathered in Whitehall to protest against the military action.
Mr Cameron has established a new subcommittee of the national security council, NSC (L), which will bring together the prime minister, deputy prime minister, the foreign secretary, defence secretary, international development secretary and other ministers with defence and intelligence experts. The attorney-general will attend as required.
An administrative building - described by coalition forces as a 'command centre' - at Muammar Gaddafi's complex was destroyed last night.
Military action is currently under US command. UK involvement is taking place at every level, but it seems that Downing Street is resisting efforts to have it take over full military control, preferring instead for Nato to take over.
"The UK sees Nato as the main means of coordinating military action," the prime minister's spokesman said.
French president Nicolas Sarkozy would prefer for the mission to stay outside of Nato control, and remain with the UK, US and France.
Meanwhile, Downing Street failed to come up with a clear line on whether the UK could target Col Gaddafi specifically under the UN resolution.
Defence secretary Liam Fox refused to rule out a targeted strike yesterday and Mr Hague did not answer the question when it was repeatedly issued during media interviews this morning.
But Britain's chief of the defence staff, General Sir David Richards, insisted it was "not allowed" under the resolution.
Labour's Jim Murphy branded Mr Fox's comments "irresponsible in many ways".
Mr Cameron told the Commons: "Many people will ask questions about regime change and Gaddafi and the rest of it.
"I've been clear. I think Libya needs to get rid of Gaddafi. But in the end we are responsible for trying to enforce the security council resolution. The Libyans must choose their own future."