Police and Council chiefs today urged postal voters to mark their ballot papers in secret and post them to the elections office themselves in the local council poll on May 1.

They warned potential vote-riggers trying to abuse the system that stringent checks were in place and pledged that any evidence of abuse would be fully investigated.

The Telegraph & Argus revealed exclusively last Saturday that about 37,000 people would be voting by post, and applications were still coming in to the elections unit.

Last year allegations that people had been threatened and intimated into giving away their postal ballot papers came flooding in to the Council.

A number of the cases were reported to the police but no prosecutions resulted.

Applications for postal votes have soared since the Government lifted restrictions to allow anyone to use the system. As a result this year's figure will be well in excess of 1,000 more than last year's total.

Bradford's total is one of the highest in Britain, however, and only about 28,000 people have registered in Leeds.

Bradford Council's chief executive and returning officer Ian Stewart said: "Under new Government legislation some voters are taking up the option of postal voting and there have been suggestions that the system could be open to abuse.

"I assure people we will take measures to ensure the process is as fair as it possibly can be. If there is evidence or allegations of abuse, either in applications for postal votes or the way in which votes are submitted, they will be fully investigated."

Chief Superintendent Phil Read, speaking for Bradford police said: "We have been working closely with the Council to make sure the local elections run smoothly and safely.

"People must not let anyone else fill their forms in for them. They must sign the forms themselves and they must post them themselves. No-one should interfere with anyone else's postal vote."

The council's elections unit is advising postal voters to mark their ballot papers in secret. They should have their identities confirmed by people they trust and post completed forms back without delay.

People who want to vote by post have until 5pm next Wednesday to submit applications to the City Hall electoral unit or Keighley, Ilkley or Shipley town halls.