Britain will maintain "robust action" against Colonel Muammar Gaddafi's regime as "appalling violence" continues against Libyan civilians, William Hague has insisted.
The Foreign Secretary said the case for continuing military strikes remains "utterly compelling", and he dismissed the regime's claims it had ordered a ceasefire as an "utter sham".
Mr Hague told MPs air strikes are relieving pressure on civilians in Misrata although the hospital is "swamped" with casualties. Ajdabiya continues to be under attack, with reports that civilians are being killed by tank shelling.
"This underlines the appalling danger its inhabitants would be in without coalition action, as do continued threats by Gaddafi forces to 'massacre' residents in areas under bombardment," he said.
"Our action is saving lives and is protecting hundreds of thousands of civilians in Benghazi and Misrata from the fate that otherwise awaited them. That is what UN Security Council Resolution 1973 was for and that is why we are implementing it."
He said UK forces had so far taken part in 59 aerial missions as well as the air and missile strikes.
Britain was involved in a co-ordinated action against Libyan air defence systems on Wednesday night, with Tomahawk Land Attack Missiles launched from a Trafalgar Class submarine .
Updating MPs in a Commons statement, Mr Hague said: "The case for this action remains utterly compelling. Appalling violence against Libyan citizens continues to take place, exposing the regime's claims to have ordered a ceasefire to be an utter sham."
The Foreign Secretary also told MPs he wants to see operations move from the command of the United States to Nato "as quickly as possible".
"We need agreement to unified command and control for it to be robust, and we expect to get that soon," he said.