The Chartered Institute of Personnel and Development (CIPD) has criticised the government's proposals for a Single Equality Bill, for failing to back the use of hypothetical comparators for equal pay claims.

Comparisons are made in equal pay cases where the claimant works in a mixed sex environment, by identifying a person of the opposite sex who receives better pay or benefits for doing the same work, or work of equal value. If such a person does not exist then hypothetical comparators can not currently be used.

The consultation document on the Bill moots the possibility of using hypothetical comparators in these cases, but the government is not supportive of such a move and says: "We consider there is a combination of practical and legal reasons why hypothetical comparators should not be permitted in equal pay cases".

Dianah Worman, adviser for diversity at the CIPD, said it would be inconsistent to rule out the use of hypothetical comparators, as the process is followed in other discrimination law and could be useful where normal comparators are unavailable.

The CIPD's consultation response said: "Denying the use of a technique because it is seen to be 'too difficult' will stop progress being made."