A baby and several other children were among more than 900 people risking the perilous journey across the Channel aboard small boats on Tuesday.
More than 500 people were intercepted by French patrols and turned away, the Home Office said, but at least 405 people managed to reach the UK.
More than 2,600 people have succeeded in reaching British shores aboard small boats so far this year, according to Sky News analysis.
Around 100 more are believed to have been brought into Dover port on Wednesday.
On Tuesday several children including a baby arrived at Dungeness in Kent aboard an RNLI lifeboat, while others were picked up by Border Force.
Families were wrapped in blankets as they were brought up from the beach, with children carried up the shore by lifeboat crew and police officers.
In Dover, a toddler wearing a blue and green life jacket and a hooded parka smiled as they were helped up to the quayside.
Home Office minister Tom Pursglove said: “The rise in dangerous Channel crossings is unacceptable.
“Not only are they an overt abuse of our immigration laws but they also impact on the UK taxpayer, risk lives and our ability to help refugees come to the UK via safe and legal routes.”
He said the government’s Nationality and Borders Bill will fix “the broken system”.
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Some 28,526 people crossed the Channel last year, according to official figures, but this is expected to almost double in 2022, a union representing Border Force workers told Sky News previously.
This year, officers have been instructed to work to an assumption that nearly 60,000 people will reach the UK in small boats, according to Lucy Moreton, from the Union for Borders, Immigration and Customs.
This is despite the dangers involved in crossing the 21-mile Dover Strait, a journey that claimed at least 27 lives when a boat sank off the coast of France in November last year.
The 60,000 figure was also calculated before the Russian invasion of Ukraine, which has prompted a massive refugee crisis as more than three million people have fled the country.
The UK Government says tens of thousands of Ukrainian refugees could come to the UK, with more than 130,000 Britons having offered up their homes as of Wednesday morning.