Police are asking the public to report any suspicious activity to help them in the battle against electoral fraud when the polls open tomorrow.

Leicestershire police said officers would be on hand across the county to ensure any offences linked to the county council and European Parliament elections were detected and dealt with.

The most likely offence would be people registering voters at addresses which are unoccupied.

Police asked the public to report people they saw visiting properties which are known to be empty, potentially to collect polling cards.

Council officers and police will also be checking postal votes for similarities in handwriting.

Voters visiting polling stations should report any harassment as they enter.

Although it is legal for party activists outside polling stations to suggest people should vote for someone, they cannot use undue influence such as threats.

Detective Sergeant Dharmendra Bhakta, of the police's economic crime unit, said: "As thousands of people leave their homes to vote in the local elections, Leicestershire police officers will be on call to respond to any polling station issues.

"In addition, they will be following leads on any postal voting anomalies which may arise.

"Leicestershire Constabulary and the courts take a very serious view of those who engage in election offences, which in some cases may result in a custodial sentence.

"It is a crime which tears the very fabric of our democratic society.

"The police service continues to support the democratic process and tackle those who would seek to undermine it."

This year, Leicestershire County Council has referred one matter to the authorities relating to the elections.

Leaked e-mails showed that deputy council leader Nicholas Rushton offered a pre-election deal to get a rival candidate to stand down in the Valley division in North West Leicestershire.

A police spokesman said today that no-one had been arrested or charged and investigations were continuing.

The city, county and Rutland elections in 2007 passed without any prosecutions.

Police were alerted after a number of voting slips appeared to have been completed in the same handwriting.

The investigation revealed they related to a man who was innocently helping retired people who did not speak English – which was legal.

Police were also called in that year when about 1,400 votes were not counted when the results of the election for the city's Abbey ward were announced on May 4.

The votes were later counted and Leicester City Council said they did not make any difference to the result.

To report suspicious activity, or if you have any information about those committing suspected electoral fraud, call police on 0116 222 2222.