Paul Hills, managing director of EDO, has been giving evidence at the trial of two anti-arms protesters from campaign group Smash EDO .

Under cross-examination he spelled out a range of arms contracts the factory is involved in and said the firm is not breaking UK law.

Jessica Nero and Gavin Pidwell deny committing aggravated trespass by gluing and locking themselves to the gates of the factory in Home Farm Road, Moulsecoomb, on April 26 last year.

Their defence is that they were not obstructing or disrupting people in their lawful activity because the work of the factory was not lawful.

Mr Hills was called as a witness to the protest but was also questioned for more than three hours about the company’s work.

He confirmed the factory makes a cable called a field replaceable connector system (FRCS) for Tornado aircraft. The “umbilical” cable – which looks like a washing machine hose – gives guidance information to a bomb and separates from it when it is dropped.

He said the firm does not currently make them for the US government. But he confirmed the firm does have a “development contract” with arms company Lockheed Martin to design them for the F35 joint strike fighter.

The programme involves the UK, as well as the United States and Israel – who are not bound by the UK’s Cluster Munitions (Prohibitions) Act.

The law makes it illegal to assist any other person in using a cluster bomb – a bomb which releases smaller bombs.

Victoria Kerly, defending Nero, asked Mr Hills whether he could be sure the FRCS cables EDO makes would not be used as part of a mechanism to release cluster bombs.

She said: “You cannot be certain that your product which ends up on planes for the American air force does not enable the use of cluster bombs, can you?”

Mr Hills said: “We are very clear what it is used for. We have not been used to qualify for fitting to any weapons that are classified under the Cluster Munitions (Prohibition) Act 2010.

“I can’t stop somebody doing something wilfully with our product without our knowledge.”

He later said: “If somebody wilfully chooses to do that, we are not assisting in doing so.”

He said Israel does not use the versions of the F16 for which EDO supplies cables.

Miss Kerly produced promotional material used by EDO in 2007 including a claim that its FRCS cable had been “fitted and tested” for equipment used by NATO countries including a “joint standoff weapon”.

Mr Hills said the equipment had not been “qualified and sold” or supplied for that weapon and he did not think it was a cluster bomb. He also said a presentation described by EDO’s design director at a conference in Seattle this year which included references to “sub munitions dispensing from munitions” did not refer to cluster bombs. He said: “The technology we are looking to develop here does not cross into the boundary of the cluster munitions prohibition act 2010. The submunitions we are looking at do not contravene that act.”

Nero, 35, of Graham Road, Mitcham, Surrey, and Gavin Pidwell, 26, of no fixed abode, are due to return to court today (August 2), when police officers are expected to give evidence about the protest.

The magistrates are not expected to reach verdicts until a further hearing later this month.