Portugal Colonial - Four dead, dozens rescued from capsized migrant boat in Channel

Dozens of others were plucked from the waters of one of the world's busiest shipping lanes in a large-scale rescue operation involving UK and French emergency services.

Prime Minister Rishi Sunak, who is trying to tighten rules to prevent record numbers of migrants from attempting the crossing, called the capsize a "tragic loss of human life".

Interior minister Suella Braverman said the fatalities -- and the loss of 27 lives in November last year -- were "the most sobering reminder" of the need to cut off the route.

"Crossing the Channel in unseaworthy vessels is lethally dangerous," the immigration hardliner told parliament, promising closer cooperation with the French authorities.

"It is for this reason above all that we are trying to destroy the business model of the people smugglers."

The Public and Commercial Services (PCS) union which counts Border Force and Coastguard staff involved in the rescue as members said Braverman "should resign in disgrace".

The charity Refugee Action said the deaths were "predictable and avoidable", while the Care4Calais group called the UK's failure to make safe routes available "utterly shameful".

But Sunak's spokesman dismissed such criticisms as inappropriate. "The government is firmly fixed on resolving this issue," he told reporters.

Ministers were acting to end "vulnerable people being exploited" and the UK has accepted hundreds of thousands of individuals through safe routes for years, he added.

Government sources said earlier that 43 people were rescued, including more than 30 who had fallen overboard, with fears the death toll will rise.

- Screams -

A fisherman told Sky News he was awoken by his crew reporting screams for help from migrants in the near-freezing water next to their trawler.

The crew spent several hours plucking dozens to safety, sharing footage of the dramatic scene with the UK broadcaster, and comparing it to scenes from a war movie.

"Adrenaline kicks in and you find the strength to get these guys safe," the fisherman, named only as Raymond, said.

Nikolai Posner, from the Utopia 56 group helping migrants in northern France, said it received a voice message and location notification from a boat in distress at 2:53 am local time (0153 GMT).

"We forwarded it to the French and British coastguard by phone. At 3:40 am (0240 GMT), the French coastguard told us the British were handling it," he told AFP.

"The location that was sent to us was in French waters. At 2:59 am the person who contacted us was no longer receiving messages on WhatsApp."

Utopia 56 said later in a statement: "Although it is impossible to state with certainty that the messages came from the sunken boat, all the elements... tend to suggest they did."

The organisation said it received five calls overnight from boats attempting the Channel crossing.

The message suspected to have been made from the stricken boat said children and families were onboard and it was taking on water from the stern, submerging its occupants.

"Please help us," it said. "We're in the water."

- Pressure -

A UK government spokesman said the authorities were notified at 3:05 am about "a migrant small boat in distress".

"There have been four confirmed deaths as a result of this incident, investigations are ongoing and we will provide further information in due course," he added.

More than 44,000 migrants have made the journey across the Channel so far this year -- a record -- creating tensions between London and Paris about tougher preventative measures.

It has also piled political pressure on the UK government, which promised to "take back control" of immigration after its Brexit departure from the European Union.

Opponents have criticised the government's attempts to tighten entry rules and called its proposals to deport failed asylum seekers to Rwanda unlawful.

They have also accused ministers, including Braverman, of demonising asylum seekers and fuelling hostility towards people seeking sanctuary with inflammatory rhetoric.

Under the agreement, Albanians arriving by boat across the Channel would be immediately returned to their home country.

M.Gameiro--PC