World Bulletin / News Desk 

The EU is set to launch a naval mission on Monday against gangs smuggling migrants from Libya but it will be limited to intelligence-gathering for now because of a lack of U.N. authority or Libyan consent.

The operation is part of a stepped-up European response to a wave of thousands of people from Africa and the Middle East making the dangerous crossing from Libya to Europe.

Many have drowned in the Mediterranean, including around 800 killed in a shipwreck in April.

EU foreign ministers meeting in Luxembourg on Monday are expected to agree to launch the mission, diplomats said, but will authorise only a first phase using ships and planes to gather intelligence about the migrant traffickers' activities in international waters.

"Ministers would only be launching phase one, which is essentially intelligence-gathering on the high seas. They would only have a legal mandate to launch phase one in the absence of a Security Council resolution," one EU diplomat said.

European members of the 15-member Security Council were drafting a resolution to approve the operation under Chapter 7 of the U.N. Charter, which allows the use of force.

"What (the Libyans) are basically saying now is that 'We're not going to decide (on consent for the EU mission) until we know where we are with the Leon process,'" a senior Security Council diplomat said in New York.

"It is stuck, frankly," said the Brussels-based diplomat.

Some EU diplomats, concerned about mission creep, want a firm commitment that any decision to move to phase two or three would require separate approval by EU governments.

"You will have a bunch of boats ... sitting about 30 nautical miles (56 km) off Libya's territorial waters able in practice to serve no other useful function than search and rescue," John Dalhuisen, of rights group Amnesty International, told a news conference.