Work on the 35 m high fly-tower at the £220m Royal Opera House redevelopment was halted last week after a metal board fell from the tower, narrowly missing one worker.

Contractors were told to stop work while construction manager Schal carried out a risk assessment of working practices. Work resumed the next day after debris was cleared from all levels of the fly-tower.

Schal was unavailable for comment. However, one site worker said the operative had had a lucky escape. “He would have been decapitated if he’d been standing a foot in the other direction,” he said.

Workers have been critical of safety standards at the opera house since the dismissal of an electricians’ union safety representative earlier in the year. He is understood to be taking M&E contractor Balfour Kilpatrick to an industrial tribunal.