SCOTTISH Labour has been accused of "anti-family" politics after it was said to have blocked a deal to protect the voting rights of a pregnant Nationalist MSP.

The SNP government backed a "pairing" arrangement to cover the maternity leave of one of their members, Angela Constance.

But opposition parties blocked the request in a move that is likely to deprive the SNP of its one-seat lead over Labour when the MSP is off.

The row follows the cross-party discussions on whether a Westminster-style pairing system can be introduced at Holyrood. MPs, through being paired with a member from another party, can miss votes in the knowledge that their opposite number will not vote either.

A similar system was recently proposed for MSPs who go on foreign trips, and the SNP wanted to extend the system to other areas - to include covering Constance's maternity leave, which is expected to begin early next year.

However, the Sunday Herald understands the proposal, made by SNP business manager Bruce Crawford, was rebuffed by Labour and the Liberal Democrats.

Granting a pregnancy deal would have maintained the SNP's one-seat lead over Labour, a fact the Nationalists believe explains the rejection.

One party insider said: "It doesn't say much for Labour's much vaunted commitment to a family-friendly parliament that they said no. It is disappointing that opposition parties are not prepared to co-operate on this."

But Labour business manager Jackie Baillie responded by saying that the SNP, when in opposition, refused to support the pairing system.

"The architects of where we are now are the SNP," she said. "They didn't support pairing in the first four years, or in the second four years. I am happy to consider, on an informal basis, a case-by-case arrangement."

She said no pairing deal was in place to cover the maternity leave of Labour MSPs Wendy Alexander, Karen Gillon and former member Susan Deacon.

An SNP spokesman said: "Absence arrangementsarediscussedonan ongoing basis."