Grim warning Sydney's covid cases could hit 3,000 by January unless the ENTIRE city goes into lockdown - as experts call for New Year's Eve celebrations to be cancelled.

Sydney reported 30 new cases of coronavirus on Sunday, 28 with confirmed links to northern beaches cluster.

Infectious disease expert Professor Raina MacIntyre said Sydney needs to go into lockdown if cases rise.

She warned about the dangers of Christmas and New Year's, predicting cases could hit 3,000 by January 8.

Prof MacIntyre said NSW needed to improve its digital contact-tracing and efficiency of testing clinics. READ MORE