Tories in Lords hit poll reform

Ministers today threatened to guillotine the Lords debate on voting reform after rebel Tory peers joined Labour to inflict a surprise defeat.

Nick Clegg's flagship plan to hold a May 5 referendum on a new electoral system was left on a knife-edge after the Lords voted to require a minimum 40 per cent turnout for the result to be valid.

The Labour amendment was backed by 10 Tories.

Reversing the decision will add another delay to the Bill, which must be passed by a strict deadline of February 16 for the referendum to be held on schedule.

A senior Lib-Dem source said the Government was keeping open the "nuclear option" of cutting short further debate in the Lords, which would spark a major row.