Employers "need to follow the rules" and not bring staff in to work for anything other than "essential" tasks, Scotland's finance secretary has said.
People have been urged to work from home while the UK is in "lockdown" to curb the spread of coronavirus.
Kate Forbes said businesses should not ask staff to come in unless their work is essential in fighting the virus.
She also called for the Treasury to find a way to get more direct support to self-employed people.
And she said banks should be "sympathetic" to requests for deferred payments and mortgage holidays, saying the next few months would be about "ensuring that we still have an economy at the end of it".
The country went into a state of "lockdown" on Monday in a bid to slow the spread of Covid-19 and ease pressure on health services.
People have been told they "must stay at home" if at all possible, with only limited trips out of the house for exercise, to buy supplies or attend essential work.
However, there have been concerns that some firms are still asking staff to come in to work.
Ms Forbes said the guidance was "crystal clear", and that it "shouldn't be for employees to be feeling anxious right now about whether or not they should be going into work".
The finance secretary told the BBC's Good Morning Scotland programme: "If staff cannot work from home, employers should ask themselves whether the business is essential to the fight against coronavirus.
"Now there are obviously firms in that category, whether that's making medical supplies or whether it's relevant to the wellbeing of the nation in terms of food supplies.
"But if that is not the case, then businesses without question should not be asking their employees to come into work.
"The only way that we fight this virus, the only way we save lives, the only we stop it in its tracks is by staying at home, and there is a responsibility on all employers to take that seriously. They are not the exception to the rule - they need to follow the rules."
Ms Forbes said firms should "err on the side of doubt", and "if your work is not essential and people cannot work from home, then that work must stop".
She said construction sites should close unless they are required for a vital project such as a hospital.
Ms Forbes also called for the UK government to find a way to get support to self-employed people.
The government has moved to subsidise the wages of direct employees, but faces difficulties in identifying who is self-employed and how much support they need or could expect.
The MSP said: "I think there is a will there to help self-employed people - the question is around delivery. But there are 330,000 self employed workers in Scotland, they are absolutely critical to the economy and they're struggling just as much as employees are.
"We think there must be a credible mechanism to support the self-employed. The difficulty is that the best way of doing that is probably through the tax system. HMRC know the tax status and how much self-employed people have made. That's reserved, which is why our calls are targeted at the Chancellor."
Ms Forbes also said she would expect banks "to be keen on deferring payments right now" and to be sympathetic to requests for payment deferrals and mortgage holidays
"This is about getting through the next few months is about ensuring that we still have an economy at the end of it. And that businesses that have struggled can bounce back and people have money in their pockets," he said.
"So if there are cases where banks are not sympathetic then I will most happily put pressure on them. We expect the banks to do their bit to support communities and support businesses through the next few months."