Ministers are considering recommendations for ethnic minority-only shortlists to increase the number of black and Asian MPs. A report, commissioned by equalities minister Harriet Harman and written by lobby group Operation Black Vote, is expected to recommend changes to race discrimination laws.

It concludes that without allowing parties to impose all-black shortlists, or positively discriminate, it would take more than 75 years for parliament to reflect the ethnic make up of Britain.

Currently only 15 out of 646 MPs are from ethnic minorities, and only two of those are women. The report will be published shortly.