The EU naval mission to tackle people smuggling in the central Mediterranean is failing to achieve its aims, a British parliamentary committee says.
In a report, the House of Lords EU Committee says Operation Sophia does not "in any meaningful way" disrupt smugglers' boats.
The destruction of wooden boats has forced the smugglers to use rubber dinghies, putting migrants at even greater risk, the document says.
Operation Sophia began in 2015.
It was set up in the wake of a series of disasters in which hundreds of migrants died while trying to cross from Libya to Italy.
The EU authorised its vessels to board, search, seize and divert vessels suspected of being used for people smuggling.
'Responding to symptoms'
The report states that "the arrests made to date have been of low-level targets, while the destruction of vessels has simply caused the smugglers to shift from using wooden boats to rubber dinghies, which are even more unsafe".
It says that there are also "significant limits to the intelligence that can be collected about onshore smuggling networks from the high seas".
"There is therefore little prospect of Operation Sophia overturning the business model of people smuggling," the document concludes.
It adds that the mission is still operating out in international waters, and not — as originally intended — in Libyan waters.
The weakness of the Libyan state is seen by the report's authors as another key factor.
They say the absence of a formal invitation from Libya is preventing European Nato members from launching a military intervention, aimed at tackling the threat posed to Libya — and the wider region — by so-called Islamic State.
"However valuable as a search and rescue mission, Operation Sophia does not, and, we argue, cannot deliver its mandate. It responds to symptoms, not causes."
The report also urges the EU to urgently develop a strategy aimed at tackling the root causes of mass migration.
At the same time, the document credits the mission with saving about 9,000 migrants since Operation Sophia was launched.
The mission is named after a baby born on an EU ship that rescued her mother off the coast of Libya in August 2015.