The Government has been accused of trying to "bully" an independent elections watchdog into scrapping ballot boxes in Bradford.

Shipley MP and elections minister Chris Leslie warned that the House of Lords must "back down" in the row over the introduction of postal voting in the region.

During a heated Commons debate last night, the Tories claimed ministers tried to browbeat the Electoral Commission into supporting all-postal voting in local and European elections in Yorkshire and the Humber on June 10, which will see every one of Bradford Council's 90 seats contested.

The Commission initially proposed the voting trial in two regions - the North East and east Midlands.

However, ministers ignored the advice and announced plans to extend the pilot scheme to Yorkshire and the Humber and the North West - despite concerns about vote-rigging.

Conservative local government spokesman Nick Hawkins accused ministers of "leaning on" returning officers into overcoming their scepticism for all-postal ballots. He said: "We fear Labour has sought to intimidate returning officers into changing their views."

His claim came as MPs voted by 308 to 185 - a majority of 123 - to overturn a Lords proposal to carry out the pilot scheme in just two regions.

Peers called for the independent Electoral Commission to make the final decision. The Lords has thrown out Government plans to hold trials in four regions three times - preferring just two.

Mr Leslie said: "The House of Commons has made its view known; it has repeated its view; the Lords must now back down on this issue."

He added: "Returning officers... are now more resolute and more certain that they want to proceed with all-postal voting."

The move will be seen as a challenge to peers with time running out for electoral registration officers to make the necessary preparations.

Deputy Prime Minister John Prescott branded peers' defiance "totally unacceptable".

The European Parliamentary and Local Elections (Pilots) Bill returns to the House of Lords tomorrow.