Dozens of workers, employed to renovate the Sydney Opera House, will meet outside the site to discuss concerns after being potentially exposed to asbestos on the job for almost a week.

The Electrical Trades Union on Tuesday moved to halt renovations after tests confirmed the presence of asbestos.

The 25 workers on the project were at risk from the asbestos for almost a week, the union said in a statement.

Building company Laing O’Rourke insists a comprehensive asbestos management plan was in place but it is understood the meeting is taking place because workers remain concerned proper steps were not taken following the discovery of breathable fibres.

The union is angry it wasn’t notified promptly after the builder and electrical contractor reportedly first made aware of the issue on July 24. Asbestos Safety and Eradication Agency called for an urgent program to remove high-risk asbestos from the nation’s buildings.

By Perry Duffin