Gordon Brown is planning to apologise for the UK's role in sending thousands of its children to former colonies in the 20th century, the BBC has learned.
Under the Child Migrants Programme - which ended just 40 years ago - poor children were sent to a "better life" in Australia, Canada and elsewhere.
But many were abused and ended up in institutions or as labourers on farms.
The move comes as Australia's Prime Minister prepares to apologise for the mistreatment of the cihldren.
Mr Brown has asked officials to consult with survivors of the Child Migrants programme, so that a statement can be made in the new year.
Meanwhile, on Monday, Australian prime minister Kevin Rudd will deliver a national apology to the "Forgotten Australians" and will recognise the mistreatment and ongoing suffering of some 500,000 people held in orphanages or children's homes between 1930 and 1970.
He will combine it with an apology to the 7,000 child migrants from Britain who live still in Australia.
As they were compulsorily shipped out of Britain, many of the children were told - wrongly - their parents were dead, and that a more abundant life awaited them.
Many parents did not know their children, aged as young as three, had been sent to Australia.
Child care agencies worked with the government to send disadvantaged children to a rosy future and supply what was deemed "good white stock" to a former colony.
In many cases they were educated only for farm work, and suffered cruelty and hardship including physical, psychological and sexual abused.
In a letter to the chairman of the Health Select Committee this weekend, Gordon Brown said "the time is now right" for the UK government to apologise for the actions of previous governments.
"It is important that we take the time to listen to the voices of the survivors and victims of these misguided policies," he wrote.
Kevin Barron, chairman of the health select committee - which has looked into what happened - said he was "very pleased" to have received a written commitment from Mr Brown.
"After consultation with organisations directly involved with child migrants we are going to make an apology early in the new year," he said.