The local authority said it would allow a judge - rather than its own social workers - to decide if the Bramleys were suitable parents for half- sisters Jade, five, and Hannah, three. It added that it would not oppose a new application to adopt the girls.
Mr and Mrs Bramley have been on the run for the past four months, disappearing hours before a meeting at which they were due to hand back the children they had looked after for the previous six months.
Cambridgeshire social services department has said it considered the couple unsuitable parents for the girls, partly because they were too strict. Council officials have maintained that their decision to take Jade and Hannah away was correct.
But last night, in an open letter to the couple, the social services director, Liz Railton, said: "I know the last four months must have been extremely difficult for you all, but it cannot be in Jade and Hannah's long-term interests for you to stay away any longer. I am therefore proposing a way that will enable you to come home quickly."
She said that in the long term the future of the children would be left up to the courts. A spokeswoman added: "In the short term they can keep the children, providing the court gives them the OK to do so."
The move was at least partly prompted by the first stage of legal action by Jade and Hannah's natural mother, Jackie Bennett, who hopes to gain some access to her children.
Raphael Silver, her solicitor, said: "On Jackie's behalf, we have today started legal proceedings, the purpose of which is to ask a court to decide what is in the best interests of Jade and Hannah. She is confident, that the court... will take all relevant matters in to consideration. Jackie hopes that by taking this action, Mr and Mrs Bramley will feel more capable of returning the children safely and speedily."
There have been a number of apparent sightings of the family, the most recent being 10 days ago on a steam train in North Yorkshire. Earlier this week the couple sent a letter to newspapers and a television station, pleading to be allowed to keep the children.Reuse content