Millions of Australians have started receiving text messages warning them of the seriousness of the widening coronavirus outbreak.

In a campaign that started on Wednesday, every Australian mobile phone will be sent a text message from the federal government urging them to protect their own health, and their families and the community.

Federal Health Minister Greg Hunt said nearly 36 million messages would be sent in coming days.

This message will be sent to 36 million Australian mobile numbers. Photo: Federal Government

But there is already confusion about the contents of the text, which urges Australians to stay home if they are sick.

That appears to contradict advice from Prime Minister Scott Morrison, who announced tougher restrictions on movement on Tuesday night.

“Stay at home unless it is absolutely necessary you go out,” Mr Morrison said of the stricter rules, which will be enforced from midnight on Wednesday.

State premiers have also conveyed sterner messages. Victorian Premier Daniel Andrews has already flagged more stringent controls on movement and business in his state.

“I can make all the rules in the world. But if people don’t follow them then Victorians will die,” he said.

“If you can stay at home, you must stay at home. It is very, very simple.”

But, on Wednesday, the Prime Minister defended the apparent difference between his latest advice and the message going to mobile phones.

“The most urgent message that we’re getting for people to stay home is to stay home if you’re sick,” he said.

“It is also important that people should stay home when they’re in self-isolation and, as I said last night, our preference and our instruction is more generally stay home unless you’re going out for essentials.”

Mr Hunt said the initial message would be followed by others as the government stepped up its communications campaign on the coronavirus outbreak. The messages would “re-inforce the importance of abiding by new restrictions and social distancing to save lives”, he said.