A father deliberately caused chaos during a six-day crane-top protest over fathers' access rights to their children, a court heard yesterday.

David Chick's 150ft vigil near London's Tower Bridge forced police to seal off the area to pedestrians and traffic and resulted in "very grave knock-on effects" to local businesses, it was claimed.

Chick, 37, who had carried out a similar protest before, knew what he was doing but repeatedly ignored police requests to come down and end the disruption, said Anthony Wilcken, prosecuting.

He told Southwark Crown Court: "To some it may seem amusing, to some it may raise feelings of sympathy for the defendant.

"To others it may equally raise sympathy to members of the public who were seriously inconvenienced by this man's activities."

But, he said, sympathy had no part to play in deciding whether Chick caused a public nuisance between October 31 and November 5 last year, a charge Chick denies.

Mr Wilcken said: "He knew exactly what he was doing because in June the same year he had climbed if not that crane then one very like it and close to it and after about a day had been successfully talked down. And on that occasion, too, roads had been closed as a precautionary measure."

Mr Wilcken told the court Chick, of The Ridgeway, Burgess Hill, began his Fathers for Families protest at about 5am after gaining access to a large Taylor Woodrow construction site next to St Katharine's Dock.

He scaled the crane and unfurled a number of banners protesting against various organisations for not giving fathers sufficient access to their children.

Mr Wilcken said: "Indeed, in itself, you may think, or some of us may, that was not an unlaudable exercise or belief.

"But we say he went way beyond any means of legitimate and lawful activity in support of his cause."

Police were called to the scene and Inspector Jane Easton decided the defendant not only posed a threat to construction workers but to passing traffic and pedestrians.

"Nobody knew what his mental state of health was. Nobody knew anything other than somebody in a Spider-Man uniform had climbed the crane, put up some banners and posed an unknown threat."

Mr Wilcken said Chick could have even decided to make the "supreme gesture" and throw himself off. If police had done nothing to control the situation there could have been a fatal disaster.

A specialist climbing team repeatedly climbed the crane to speak to Chick and assess his mental and physical condition.

Mr Wilcken said: "During the course of their negotiations with him he made it quite clear he was staying put and would only come down when he thought it fit to do so."

The trial continues.