Dozens of migrants have been brought ashore off Dungeness - hours after 31 died near Calais while attempting to make the same journey across the Channel.
Images showed the migrants in Kent being brought ashore by RNLI workers on a rescue boat.
Women and young children were among them.
Hours earlier, an inflatable dinghy capsized near Calais, killing 31.
French maritime officials have described it as the worst-ever incident involving migrants in the Channel.
Two people were saved from the water and four suspected people-smugglers have been arrested.
Prime Minister Boris Johnson will chair a meeting of the Cobra emergency committee in response to the incident, Downing Street said.
An emergency search was sparked when a fishing boat sounded the alarm earlier on Wednesday after spotting several people at sea off the coast of France.
Speaking to Sky News, France's MP for Calais warned that the English Channel risks becoming the new Mediterranean Sea for migrant crossings unless the UK and France find a solution.
Pierre-Henri Dumont said: "We all need, both sides of the Channel, to stop making migrants an internal argument with internal policies and try to figure out how to find a solution.
"The Channel right now is becoming the new Mediterranean Sea, it's like an open sky graveyard. We must find a way to end it."
Nick Thomas Symonds, Labour's shadow home secretary, told Sky News that the international community "must act now" to stop people from "making this most perilous of journeys" after a "sobering day for the UK, for France and the wider international community".
"This is an issue that is becoming worse. We don't want to see people risking their lives," he said.
"We need to look at joint law enforcement work to try to disrupt these vile people smugglers on the routes that they facilitate to Northern France with such reckless disregard for life.
"People do not become displaced from their homes in northern France. They've taken routes that are often thousands of miles away, whether it's in Africa, across the Mediterranean, or from the Middle East and other areas where they come up through eastern and central Europe.
"If things continue as they are, then we are going to have these really tragic and awful consequences."
More than 25,700 people have made the journey to the UK in small boats this year - three times the total for the whole of 2020, according to data compiled by the PA news agency.