The government has submitted a draft proposal to Parliament on temporarily restricting freedom of movement and close contacts as well as making the wearing of face masks mandatory in areas where the epidemic is "spreading rapidly and uncontrollably".
The restrictions would apply to Helsinki, Espoo, Vantaa, Kauniainen and Turku.
"The situation is very serious. There is a very serious threat that healthcare will be overwhelmed if we do not introduce new restrictions," Prime Minister Sanna Marin (SDP) said on Yle TV news on Wednesday evening.
The government is aiming to bring the law into force "as soon as possible", but Yle sources suggest that is unlikely to happen before Easter.
Yle also understands that the restrictions would be effective for three-week periods at a time, and renewed if deemed necessary, up until 14 May.
Parliament is expected to debate the proposal on Friday.
The submission to Parliament comes after the parliamentary groups of three of the government’s coalition parties — the Swedish People’s Party, Green Party and Left Alliance — decided to support the bill after each holding marathon talks on Wednesday evening.
The other two government parties, the Social Democrats and the Centre Party, were reported to already support the proposal.
The draft bill proposes that people would be prohibited from leaving their homes except under certain circumstances, such as for essential purposes and for outdoor exercise.
Going shopping for groceries and other essentials, such as fuel, as well as trips to the pharmacy.
Going to the bank and post office.
Going to work, running a business or entrepreneurial effort.
Managing and attending medical and social care matters and visits, such as going to doctor's appointments, or managing official matters.
Attending school, from early childhood to higher education, as well as participating in matriculation exams, school entrance tests or similar situations.
Carrying out official duties.
Carrying out military service.
Caring for a close friend or family member, attending a funeral of a close friend or family member, or caring for a child or someone with disabilities.
An individual, pastoral meeting with a representative of a religious community.
The maintenance and movement of holdings such as buildings or vehicles.
Caring for an animal or exercising pets outdoors.
Travelling to a secondary residence or holiday home.
The draft proposal also allows for children aged 12 and younger to play together outdoors.
However, in areas where such legislation is in effect, all people born in 2007 or before will need to wear protective face masks in indoor public spaces, such as on public transportation and in buildings used by the public.
Individuals who fail to comply with mask requirements could face fines of 40 euros.
Meanwhile, Yle's information indicates that non-compliance of stay-at-home orders could also result in fines but the amount is not yet known. Individuals who are unable to wear face masks due to medical conditions will not be required to use them.