Police revealed today they have taken officers from front-line duties every week for more than a year to deal with protesters at a weapons factory.

More than 800 hours of police time costing at least £31,000 has been spent in 13 months guarding demonstrations at EDO MBM Technology, which makes bomb release components for fighter jets.

Sussex Police sends four constables and a supervisor along with police community support officers to each protest. They stay for up to four hours protecting staff from protesters who, it is alleged, have thrown themselves in front of cars belonging to employees.

Chief Inspector Kerry Cox, district commander for east Brighton, said: "We have been working with the company to look at a long term solution because of the impact on police resources week in and week out since the protest began.

"We recognise the right of people to protest peacefully but we also need to ensure employees have the right to go about their lawful business free from harassment."

EDO was using laws formulated to protect women from stalkers to apply for a High Court injunction today banning the Smash EDO and Bombs Out of Brighton protest groups from gathering outside the factory in Home Farm Road, Moulsecoomb.

Under the terms of the order demonstrations would be allowed for only two-and-a-half hours on Thursdays in groups of ten or less and music would be banned.

Solicitor Rizwan Majid, acting for the firm, said: "All this malarkey of the protesters saying we shouldn't be using the harassment law has fallen by the wayside. If there is harassment that is what the law is there for. If the protest was just a vocal objection to EDO we wouldn't be in court but this is not a legitimate protest.

"They have demonstrated against the directors at their homes and posters have been given out to their neighbours."

The protesters deny this and say they have not used violence or intimidation. Smash EDO's legal adviser said human rights lawyers had volunteered to represent the group and protesters had gained legal aid to fight the injunction.

Around 30 anti-war protesters stood opposite the factory's new 6ft fence yesterday and made as much noise as possible while staff watched through the windows.

Ceri Gibbons, 37, of Smash EDO, walked into the factory compound through an open gate, banging a drum.

He said: "I walked right up to the door and rang the bell. The police came and told me I wasn't allowed, I said I wanted to ask permission but he said I had to go."

Mr Gibbons was searched for weapons and then released.

Glenn Williams, of Sussex Action for Peace, said the weekly protests would continue if the injunction was served.

He said: "We have done silent protests where we just stand here and look at them. We find they have to turn away."

John Gatt, 80, said: "I am here today because they are taking away our right to protest peacefully."