David Cameron has promised to leave "no stone unturned" to halt the killing of civilians in Libya as the international community threw its weight behind demands for Colonel Muammar Gaddafi to surrender power.
The Prime Minister, in Paris for talks with French President Nicolas Sarkozy, described the situation in the besieged city of Misrata as "appalling", and he accused the Libyan dictator of deliberately ordering the murder of his own people.
"Britain and France are at the heart of this coalition and with President Sarkozy I am going to be sitting down to make sure that we leave no stone unturned in doing everything we can militarily, diplomatically, politically to enforce the UN resolution, to put real pressure on Gaddafi, and to stop the appalling murder of civilians," he said.
"It is appalling what Gaddafi is doing in Misrata. He is murdering his own citizens, including children. The orders come directly from him."
Earlier the international contact group on Libya, holding its first meeting in the Gulf state of Qatar, backed calls for Gaddafi to step down, warning that his continued presence "would threaten any resolution of the crisis".
"There should be an inclusive political process so that the Libyan people can determine their own future," it said in a closing statement.
"They called on all Libyans who wanted to see a process of political transition to urge Gaddafi to step down."
Downing Street said that Britain would be sending the rebels 1,000 sets of body armour in "non-lethal" aid from surplus UK defence stocks, in addition to the 100 satellite telephones already supplied.
Britain and France have been pressing fellow Nato members to commit more strike aircraft to operations in Libya so that they can step up attacks on the regime's tanks and artillery.
The Ministry of Defence disclosed that the RAF's force of 12 Tornado GR4s and four Typhoons based at Gioia del Colle now accounted for a quarter of the ground attack aircraft available for Nato operations.