British Prime Minister Boris Johnson on Wednesday convened top officials for crisis talks after at least 27 migrants died crossing the Channel from France to England.
Downing Street said Johnson called a meeting of the UK government's emergencies committee, as news emerged of the tragedy off the northern French coast.
The disaster is the single worst loss of life recorded in recent times from migrant crossings in the Channel, and comes as tensions grow between London and Paris over the record numbers of people braving the perilous crossing.
More than 25,700 people have made the cross-Channel journey in small boats this year -- three times the total for the whole of 2020, according to data compiled by Britain's PA news agency.
The increasing numbers of arrivals, although still below those being taken in by Britain's closest neighbours, have put Johnson's government and his interior minister Priti Patel under pressure.
"Taking back control" and securing Britain's borders was a key pledge of the "leave" campaign during the 2016 Brexit referendum to take the country out of the European Union.
But Britain -- out of the EU in full since January this year -- has found the practicalities of doing so more problematic, including the need to cooperate closely with its former EU counterparts.
Natalie Elphicke, the Conservative MP for the Channel port of Dover called the sinking "an absolute tragedy" and demonstrated the need to stop the crossings at source.
"It underlines why saving lives at sea starts by stopping the boats entering the water in the first place," she said.
"As winter is approaching the seas will get rougher, the water colder, the risk of even more lives tragically being lost greater.
"That's why stopping these dangerous crossings is the humanitarian and right thing to do."
The government has extended financial support to help French authorities combat the crossings before migrants reach UK waters.
But it has made its frustration clear with Paris that so many are still getting across, as local authorities in southeast England struggle to cope with the logistics of so many new arrivals.
The chief executive of the Refugee Council, Enver Solomon, said the deaths were "heartbreaking" and safe routes were needed for those "in desperate need of protection".
"Every day, people are forced to flee their home through no fault of their own," he added.
"Now is the time to end the cruel and ineffective tactic of seeking to punish or push away those who try and find safety in our country."
Other charities also called for the government to scrap its proposals to tighten entry restrictions for migrants crossing the Channel, and off-shore processing centres.
Plans include criminalising asylum seekers who have travelled through "safe" third countries such as France, and the targeting of people traffickers.