Supermarkets, grocery stores, bottle shops, pharmacies, petrol stations, banks, newsagencies and post offices will be allowed to stay open.

But for other businesses in the city the state government said the default was "closed" unless they fit specific circumstances laid out in pages of documentation.

Victorian Premier Daniel Andrews said the measures were expected to cause the stand downs of 250,000 workers. On top of 250,000 workers already stood down, and an estimated 500,000 people working from home, he said it meant a million people shouldn't be moving around the city.

"As heartbreaking as it is to close down places of employment, while I never thought that I would be telling people not to go to work, that is what we have to do in order to stop the spread of this wildly infectious virus, this deadly virus," Mr Andrews said.

Other retailers, some manufacturing businesses and administration businesses will be forced to close by 11.59pm on August 5 for six weeks.

Retail stores will be able to have contactless "click and collect" arrangements and hardware stores will be able to stay open for tradespeople only.

Workplaces allowed to remain open will be doing so under new strict conditions, including reductions on the number of people onsite. In the meat industry just two-thirds of workers will be able to be on site, as well as warehousing and distribution centres in Melbourne.

Meatworkers will also be subject to personal protective equipment protocols equal to that of health workers, to reflect the high number of cases associated with the sector.

The construction sector, which has so far remained open across the country, will in Melbourne move to what Premier Daniel Andrews has called "pilot light levels" with just the minimum people on site needed for safety reasons.

Mr Andrews discouraged people from panic buying months worth of groceries, saying supermarkets would stay open and would have the "fullest range they can possibly have".

All businesses that will be forced to close in Melbourne will be eligible for a $10,000 grant from the state government, while businesses closing in regional Victoria under stage three restrictions will be eligible for $5000 grants. Mr Andrews signalled there would be further announcements about business support measures.

On Sunday the government announced the greater Melbourne area would go into strict stage four lockdown measures, including a night time curfew and bans on moving more than five kilometres away from one's home.

Mr Andrews also signalled more businesses would need to close, and the state government spent Sunday night and Monday finalising the list.

Regional Victoria will also move to stage three restrictions on Thursday, even though the cases are still concentrated in the state's capital.

Victoria recorded another 429 cases of coronavirus on Monday, and 13 more people have died from the disease in the past 24 hours. Eight of the deaths are connected to aged care facilities.

Just 36 of the new cases have been linked to known outbreaks.

It brings the number of active cases in the state to 6489, with 416 people in hospital, including 35 in intensive care.

Despite the move to new strict measures, chief health officer Brett Sutton said the stage three measures had been effective at flattening the curve of infection, but the number of cases had plateaued at about 400 or 500 cases a day.

"These restrictions are very substantial, and I expect, absolutely expect that we will see transmission driven down and cases to decrease over time," Dr Dutton said.

"We don't see it in the numbers instantaneously."