The Conservative Parliamentary candidate for Watford has quit following his arrest by officers probing a three-year hate campaign.

Yesterday, the Watford Observer exclusively revealed Ian Oakley had been arrested and then bailed by police investigating the harassment of several Liberal Democrat councillors in the town.

Mr Oakley was arrested on Friday and a Conservative spokesman last night confirmed he has now stood down as the party’s candidate for Watford.

The investigation, nicknamed Operation Tuition, has been coordinated by Hertfordshire Constabulary's major crime task force.

The allegations relate to the sustained harassment of Liberal Democrats in the town, some of whom have suffered vandalism to their personal property and received malicious phone calls.

Several councillors have had abuse scratched into their cars and their tyres slashed, while others have had vile graffiti daubed close to their home.

Some councillors have even had pornography sent to their houses.

Nascot councillor Mark Watkin has also been the victim of a vicious poison pen letter campaign that made unfounded sexual allegations about him.

Police yesterday confirmed a 31-year-old man had been arrested in relation to the incident.

Mr Oakley has not been charged and is now on police bail pending further enquiries.