Premier Gladys Berejiklian announced the state endured its worse day of the current outbreak on Tuesday, with 356 new cases detected to 8pm Monday.

All rugby league in Greater Sydney, including Wollongong and Shellharbour, has been on hold since lockdown was first called on June 26. The lockdown was subsequently extended to August 28 and appears all but certain to be extended once again as case numbers continue to rise.

With the NSWRL's semi-finals scheduled for September, the board made the call to abandon its major competitions, including the NSW Cup, NSW Women's Premiership, Jersey Flegg Cup, Ron Massey Cup and Sydney Shield.

The Illawarra first grade competition forms the southern conference of the NSWRL's Presidents Cup - classed as a major competition - that also includes Newcastle and Ron Massey competitions.

The premiers in each, and a 'wildcard', were set to contest the Cup finals in September, which now won't occur.

There remains the slimmest of possibilities Illawarra and Newcastle could crown its own champions if the government were to ease lockdown restrictions outside of Sydney.

However, with Newcastle having joined Greater Sydney in COVID lockdown, it seems unlikely, with the governing body to make a call on all community football on Monday next week.

"With the current Public Health Order in force until at least August 28, and there understandably being no current NSW government sanctioned roadmap out of the lockdown for sport, the board was left with little option but to cancel our major competitions," NSWRL CEO David Trodden said.

"In reaching their decision, the board considered its obligation to provide participants with a safe environment to play sport. The NSW Government's health advice, particularly the state of infection rates and vaccination rates, made it difficult to provide that environment in the immediate future."