Govan Law Centre has lodged papers at the Court of Session seeking an interdict to prevent the eviction of an asylum seeker in Glasgow.
It is hoped the case against Serco and the UK's Home Secretary will be heard in the next few days.
Serco, who are contracted by the Home Office to provide accommodation for asylum seekers, issued notices to six individuals on Monday.
They have been told their locks will be changed in seven days' time.
As a result of the move two Afghan men facing eviction have gone on hunger strike outside the Home Office in Glasgow.
Rahman Shah and Irwais Ahmadzai are among 300 asylum seekers in the city facing eviction by Serco after being refused refugee status.
But Serco says it often has to provide housing without recompense, sometimes for months, for failed former asylum seekers who have no right to stay in the UK.
Historically, lock changes have not been used for those who remain in asylum accommodation despite the Home Office ruling they will not be granted refugee status and withdrawing their funding and support.
Serco insists it is "sympathetic" to those affected, but the company has been heavily criticised by politicians and refugee charities, who accuse it of putting profit before people.
About 500 people gathered in the city centre on Tuesday evening to protest against Serco's move and to show solidarity with refugees and asylum seekers, with further protests held on Wednesday.
Glasgow City Council says it is in the process of establishing a task force to respond to the "emerging humanitarian crisis" and has written to Home Secretary Sajid Javid urging him to instruct Serco to pause its plans.
A spokesman for the Home Office said asylum seekers who would otherwise be destitute are provided with free, fully furnished accommodation while applications are considered.
On Wednesday Serco responded to the council letter and pledged families will not be put at risk over the next month.
The firm also denied claims it has failed to engage with local authorities and it said it is saving the council a bill in excess of £1m a year for 330 people who are no longer receiving support from the Home Office.