Small and medium businesses in NSW will be eligible for weekly cash payments of up to $10,000, and adversely affected workers will receive between $375 and $600 a week, in an escalation of support measures the federal government says will be the new national template for lockdowns.

The measures, which will cost the NSW and federal governments an estimated $5 billion between them, were unveiled on Tuesday, ahead of an announcement by NSW Premier Gladys Berejiklian that the lockdown of Greater Sydney will not be lifted on Friday but will enter a fourth week, and most likely longer.