Two boats containing 40 migrants, including children, have been intercepted off the Kent coast.
All those on board said they were from Pakistan, Iran and Afghanistan, the Home Office said.
All the migrants have been medically assessed and transferred to immigration officials, a spokesman said.
An eyewitness said he saw one boat off St Margaret’s Bay in Kent at about 05:30 BST with the occupants being given life vests before being rescued.
Paul Jolliffe told the BBC he heard a siren and looked out of his window to see a Border Force boat.
He said officers used loud hailers to talk to the migrants before they were transferred to the Border Force vessel.
A total of 794 people have been intercepted in small boats since 3 November 2018.
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The Home Office spokesman said: “Anyone crossing the Channel in a small boat is taking a huge risk with their life and the lives of their children.
“It is an established principle that those in need of protection should claim asylum in the first safe country they reach and since January more than 35 people who arrived illegally in the UK in small boats have been returned to Europe.”
A note on terminology: The BBC uses the term migrant to refer to all people on the move who have yet to complete the legal process of claiming asylum. This group includes people fleeing war-torn countries, who are likely to be granted refugee status, as well as people who are seeking jobs and better lives, who governments are likely to rule are economic migrants.