In one of her last actions as home secretary, Yvette Cooper suspended family reunion, to the dismay of refugee charities.

Gunes Kalkan, the head of campaigns at the children’s charity Safe Passage, said the change would have “disastrous consequences” for unaccompanied children trying to join their families in the UK. He added: “We’re talking about children from conflict and high human rights abuse areas, such as Afghanistan, Sudan and Iran, who have been torn apart from family in the chaos.”

Enver Solomon, the chief executive of the Refugee Council, said: “Until now, family reunion has been one of the only safe and legal routes available that allows refugees fleeing war and persecution to be reunited with their partner and children.

“Far from stopping people taking dangerous journeys to cross the Channel, these changes will only push more desperate people into the arms of smugglers.”

Mubeen Bhutta, the director of policy at British Red Cross, said: “Today’s announcement will separate families and cut off one of the only safe and managed routes for children to seek protection. The vast majority of people who use family reunion visas are children and women, often trapped in very dangerous situations.”

The International Rescue Committee (IRC), the chief executive of which is the former Labour foreign secretary David Miliband, called the move “deeply alarming”. Flora Alexander, the IRC’s UK executive director, said: “Narrowing access for people seeking to reunite with loved ones is not a solution to system pressures; it risks pushing more people toward dangerous journeys.”

Yvette Cooper said that the scheme was being exploited by people smugglers, as they were using it to promote dangerous Channel crossings. She told MPs that reforms to family reunion routes would be debated in the Commons in October, and would become law in the spring.