Sydney is heading for a probable lockdown, as the super spreader event across Sydney gets worse.

A man who worked as a driver of airline workers has spread the new Delta strain of the virus far and wide with dozens of people now infected.

ABC NSW Political reporter Ashleigh Raper reports tonight that the Premier is likely to announce a full lockdown if things get worse.

On ABC News 7pm in Sydney, Raper said Gladys Berejiklian would announce a lockdown by the end of the week, in response to the fast-spreading Sydney COVID cluster.

Mask wearing across Sydney is now mandatory and people are advise to work from home if they can.

Thousands of people are isolating after being exposed to the virus at various venues acorss Sydney.

At least 30 people at a birthday party were directly exposed to the virus, including children.

Residents in seven local government areas in Sydney have their movements restricted and are effectively barred from entering Queens