Child among the dead hours after the British government approves a bill to deport some asylum seekers to Rwanda.
The boat carrying 112 people set out from Wimereux, about 32km (20 miles) southwest of the French port of Calais, to cross one of the busiest shipping lanes in the world.
Rescuers picked up 49 people, and four were taken to hospital, but others stayed on the boat and continued their journey to Britain.
“A tragedy occurred on a boat overloaded with migrants early this morning. We deplore the deaths of five people, a seven-year-old girl, a woman and three men,” local prefect Jacques Billant told reporters on Tuesday.
“The engine stopped a few hundred metres away from the shore, and several people fell into the water.”
The French coastguard said 58 people stayed on board and it was still searching for any other survivors.
“They did not want to be rescued. They managed to restart the engine and headed towards Britain,” Billant said.
More than 6,000 people have arrived in Britain this year on small, overloaded boats that risk being lashed by waves as they try to reach British shores.
The United Kingdom’s government has spent two years working to get approval on a divisive policy to send asylum seekers to Rwanda. The UK Parliament finally passed legislation overnight to allow the deportations.
Prime Minister Rishi Sunak said he expected the first flights to take off in 10 to 12 weeks, giving time for further legal challenges from charities, campaigners and unions.
Sunak told reporters on Tuesday that the government was acting out of compassion, wanting to prevent people smugglers from pushing vulnerable people out to sea.
“They are packing more and more people into these unseaworthy dinghies. You’ve seen an enormous increase in the numbers over the past few years,” he said. “This is what tragically happens.”
Under the Rwanda scheme, anyone arriving in Britain in an irregular way after January 1, 2022, will be sent to Rwanda, about 6,400km (4,000 miles) away. More than 50,000 people have arrived since that date, according to official figures.
Both the United Nations refugee agency and the Council of Europe called on the UK on Tuesday to rethink its plans over fears it could damage international cooperation on tackling the global migration crisis.
The first planned deportation flight to Rwanda in June 2022 was blocked by European judges. The following year, the UK’s Supreme Court ruled that sending asylum seekers on a one-way trip to Kigali was illegal and would put them at risk.
Other European countries, including Austria and Germany, are also looking at agreements to process asylum seekers in third countries.