Ms Mogherini also said that the EU would adopt a new accord on migration in Brussels on Wednesday. “No refugees or migrants intercepted at sea will be sent back against their will,” she said.

Under the accord, Britain is expected to be forced to take in tens of thousands of refugees to redistribute migrants across Europe. The controversial quota system could double the number of asylum-seekers in Britain from about 30,000 to more than 60,000.

France’s interior minister Bernard Cazeneuve on Monday said his country supported the plan.

European members of the Security Council, including British officials, are drafting a resolution that would allow European forces, including the Royal Navy, to conduct operations against the gangs and destroy empty boats in international waters and also in Libya’s territorial waters.

A vote may be held next week if Russian objections can be overcome.

Drone strikes and air bombing raids against the gangs’ sites on Libyan soil have also been discussed, but Western diplomats involved in the talks insisted that there was no question of a ground force. “There will be no boots on the ground,” said one official.

The risks involved in military action in the conflict-plagued country were immediately clear as representatives of its rival governments criticised the plans, with one leader warning that they would be an “act of war”.

Libya’s ambassador to the UN, Ibrahim Dabbashi, told the BBC that his country was against the proposal. “We want to know how they can distinguish between the fishers’ boats and the traffickers’ boats,” he said.

In another reminder of the dangers, a Turkish freighter came under artillery and aerial fire from unidentified attackers near the Libyan coast, leaving one crew member dead and several injured, Turkey’s foreign ministry said.

Human smuggling gangs and Islamic terrorist groups have taken advantage of the chaos in Libya since the overthrow of its long-time leader Muammar Gaddafi to establish bases in the country.

Europe’s chief diplomat said the priority was to tackle the root causes of the tide of migrants attempting to reach Europe in the perilous journey across the Mediterranean from North Africa and the Middle East.

“Europe has for once woken up,” said Ms Mogherini. “We need the rest of the world to do their part as well.”

She described the migrant crisis as “not only a humanitarian emergency but also a security crisis since smuggling networks are linked to and finance terrorist activities”.

It is not clear exactly what sort of military action the EU is contemplating. But David Cameron, in the days before the general election, said the aim of any military intervention should be to “smash the gangs” operating in Libya.

Britain has deployed to the Mediterranean the Royal Navy’s flagship, HMS Bulwark, which carries helicopters and Royal Marine commandos, as well as two patrol vessels.

Some 60,000 people have already tried to cross the Mediterranean this year, according to the UN estimates, while at least 1,800 people are feared to have drowned so far this year, a 20-fold increase on the same period in 2014.