Ministers want new adoption guidance to allow families who meet existing criteria for a child to be able to adopt regardless of their race.
Under new guidance to be issued next week, councils will be told that preventing families from adopting children of a different ethnic group “is not child-centred and is unacceptable”.
The new guidance will state if a family has met the “emotional and developmental needs” of a child officials are to ignore their ethnic origin.
The guidance does not change the law but will make clear that race should not be a “deal-breaker” if the prospective adopters show that they are able to parent the child.
Current advice states that social workers must give “due consideration to the child’s religious persuasion, racial origin and cultural and linguistic background”.
But the government believes these rules are not being interpreted properly by social workers, who are using race as their deciding factor.
The new “strengthened” guidance also makes clear that single prospective parents should not be discriminated against.
It also warns social services against delaying placing a child with a suitable family of a different ethnicity.
Figures show that ethnic minority children can wait, on average, up to three times longer than white children to be placed with an adoptive family. In extreme cases some are not adopted at all.
“Time is not on the side of the child and a delay in placing a child with a new family can damage their development, contribute to further emotional harm, reduce their chances of finding a permanent family or increase the chance of adoption breakdown,” the guidance will say.
“The social worker must not delay placing a child with a prospective adopter because the prospective adopter is single, older or does not share the child’s racial or cultural background.
“Instead of placing obstacles in the way of families seeking to adopt a child of different ethnicity, they should be properly trained to cater for its cultural needs.”
It found that in some examples the chances of being adopted reduced by “nearly a half for every year of delay”.
The Education Department last night confirmed reports that the guidance would be published on Tuesday by Michael Gove, the Schools Secretary, who was adopted.
Each local authority and adoption agency will be “closely monitored and those that break the new rules will be “named and shamed”, it was reported.
In January Martin Narey, the outgoing chief executive of Barnardo’s, said Britain was facing a dangerous collapse in adoption rates.
She cited the prejudiced attitudes of some local authorities and adoption agencies towards white parents adopting minority ethnic children as one of the reasons.
Only 70 babies were adopted last year compared with 4,000 in 1976.
Mr Narey blamed the reluctance of agencies to allow white couples to adopt black children as one of the major reasons for the decline, saying:
“The law is very clear,” she said. “A child should not stay in care for an undue length of time while waiting for adoptive parents of the same ethnicity.
“But the reality is that black, Asian and mixed-race children wait three times longer than white children.”
A recent survey disclosed widespread poor practice among adoption agencies. The Adoption UK research found that prospective parents are frequently unfairly rejected or forced to endure waits of up to six months after their initial inquiry, three times longer than legislation demands.
An Education Department spokeswoman said last night that the current guidance was to be “strengthened” to reflect current attitudes.
“We have been clear that ethnicity should not be a ‘deal breaker’ for parents to be able to adopt and should not hinder them in this,” she said.
“If parents meet the needs of a child they should not be prevented giving them a loving home.”