The scheme to allow cohabiting couples rights over each other’s money and property is being published for consultation next month. Final proposals will be drafted by next year, and supporters expect it soon to become law.
Critics are likely to see the proposals as the latest threat to the status of marriage after civil partnerships for gay couples were introduced last year.
There is concern that the timescale for the change is too drawn out. Last week, Mary Creagh, a Labour MP, put forward an early day motion calling for lone parents who have left a cohabiting relationship to receive maintenance from their former boyfriend (or girlfriend) and for a share in the joint home, even if they did not own one previously.
As many as 2m people, many of them women with dependent children, are left vulnerable to severe hardship if long-term, unmarried relationships fail.
The government has been warned that the loophole may leave Britain open to a claim that it is in breach of the European human rights convention commitment to family life by a woman claiming her boyfriend has left her homeless and unsupported.