Nato is poised to deploy attack helicopters over Libya for the first time as the international community tries to intensify pressure on Colonel Muammar Gaddafi to give up power.
Prime Minister David Cameron has confirmed that British Apache helicopters will join the latest offensive, which comes amid intelligence reports that the dictator's behaviour is becoming increasingly erratic.
The Libyan regime was looking completely isolated on the world stage after Russia joined Western calls for Gaddafi to step down.
But there are concerns that the deployment of Apaches represents a further escalation of the conflict which could breach the terms of United Nations Security Council resolution 1973.
John Baron, the only Conservative MP to oppose intervention in Libya in a parliamentary vote in March, warned that Britain was "getting down further and further into this conflict".
Mr Cameron said on Friday he had thought "very carefully" before taking the decision to deploy the helicopters for closer-quarters combat.
"As soon as you make that decision you have to be prepared as Prime Minister of our country to bear that risk," he said.
"I think very carefully before all the decisions we take. I clearly thought very carefully before we took part in any operations."
Mr Cameron added: "Three months into the operation I believe we are entering a new phase... It is right that we are ratcheting up the military, the economic and the political pressure on the Gaddafi regime so that we can enforce resolution 1973."
Russia, which has previously criticised the Nato airstrikes in Libya, signed up to a G8 communique on Friday calling for Gaddafi to step down and offered to mediate his departure.
