Britain has not ruled out arming rebels in Libya, Prime Minister David Cameron has said.
The UK is already providing some logistical equipment and military advisers to the opposition forces on the ground in Libya, as well as playing a large role in Nato-led aerial operations.
In an interview broadcast on US TV network CBS last night, Mr Cameron was asked whether he could envisage arming the rebel forces "in a more significant way".
He replied: "I wouldn't rule that out, but what we have done so far is we've helped the rebels, in line with the UN resolution 1973, to protect civilian life by giving them better communications equipment."
According to Downing Street officials, Foreign Secretary William Hague briefed Cabinet on Tuesday that Britain had to be prepared to remain involved in the Libyan mission for "the long haul".
Mr Cameron said that the allies needed to be "both patient and persistent", but insisted that progress had been made in the operation - which is in its 40th day - to protect Libyan civilians against attack by the forces of dictator Muammar Gaddafi.
"I think we should be both patient and persistent," said Mr Cameron. "Patient because, yes, this does take time to get this right. But persistent because we are doing, with our allies, absolutely the right thing.
"We must keep turning up the pressure - military pressure, diplomatic pressure, political pressure - so that we give Libyans a better chance at a better life."
He added: "When you say it's been six weeks and they haven't made progress - you know, six weeks ago we were looking down the barrel of a massacre in Benghazi, and I would say actually we've already prevented that.
"And I think the pressure needs to be turned up even further. And I've discussed that with President (Barack) Obama and I know that he takes that view, too."
Downing Street stressed that there were no current plans to arm Libyan rebels.
A spokeswoman said: "Everything that we do or potentially could do has got to be within the remit of the UN resolution and the Prime Minister is very clear on that."
She refused to be drawn on press reports that Government lawyers have advised ministers that the resolution does not allow the training of rebels or helping them to plan military missions.
The Independent quoted an unnamed senior officer saying that military top brass had privately sought clarification about the legal standing of their forces under international law.
"There is a need for clarity on what exactly (resolution) 1973 allows us," the anonymous source told the paper.
"The lawyers have been going through it with a fine-tooth comb but there appear to be some differences in interpretation and it would obviously be helpful to find out exactly where one stands."
Asked about the report, the Downing Street spokesman said: "I'm not going to get into (discussing) legal advice. The Prime Minister has been very clear that everything has got to be within the confines of the UN resolution and clearly we will continue getting legal advice on that.
"We have legal advice regarding the UN resolution."
Defence Secretary Liam Fox said the Libyan mission could be "protracted".
Dr Fox, who told a Commons committee yesterday that the operation must not be limited by spending constraints, said: "If we were at any point to say to Gaddafi 'By the way, our resolve is shaky, there may be a chance you could stay in power', what will be the effect on the Gaddafi regime? Everything we say, we have to remember, will be listened to in Tripoli."
Speaking at a Westminster lunch, he added: "We have to be very clear at all times that we are sending a consistent message, that he will not be able to remain in power and he will not be able to terrorise his people in the way he has.
"Our resolve is there and if we have to do it over a protracted period, we will do so. The idea that we would say we have got a time limit on what we are doing or we think it is OK maybe if he stays is not the message that our international partners would expect."
Dr Fox insisted that Britain was not considering arming the opposition forces in Libya.
"We have made very clear that we are not arming them and we are not training them," he said.
The provision of mentors and non-lethal equipment was purely designed to ensure they could protect civilians.
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