The Home Office contractor announced a rolling plan of lock changes in cases where asylum applications have been refused and tenants have not moved on.
A week after the policy emerged, Serco announced on Saturday it will pause the plan amid the anticipated legal challenge.
Housing charity Shelter Scotland plans to present papers at Glasgow Sheriff Court on Monday on behalf of two asylum seekers facing eviction.
Serco chief executive Rupert Soames told BBC Radio Scotland his firm would be represented in court.
The firm said it welcomed the opportunity to gain clarity from the courts, although it said it had legal advice that its approach was “fully within the law”.
Mr Soames it was not true lock change notices would be issued to 330 people.
Speaking on the Good Morning Scotland radio programme, he said: “That is the total number people we are paying for whom Home Office support has ceased.
“About of third of them have had positive decisions and will be waiting for a month or six weeks or eight weeks to find alternative arrangements and go on and make their lives with legal right to remain and nobody is going to want to make them homeless.”
Questioned on the figures regarding who would be given lock change notices, he said: “We don’t know, because a number of them, hopefully, will move on.
“We have been looking after, at our expense, people for over two years. There are 80 people who have had negative decisions, who are meant to leave the country who we still pay the rent, rate, heating, light for.”
He said Serco has made an £80 million loss on the asylum accommodation contract in the past five years.
Mr Soames added there was no space for new asylum claimants arriving in Glasgow who will “have to be put in hotels”.
He welcomed the court challenge, saying it would provide clarity and ensure the legality of the process.
Shelter Scotland director Graeme Brown said on Friday: “Our legal team will be presenting papers to Glasgow Sheriff Court on Monday morning along with the legal services agency who act for a third individual to try and get interim orders that will prevent the lock changes threatened to our clients.
“Our clients are actively working with immigration lawyers to resolve their asylum claims. Interim orders temporarily stopping the lock changes will allow this work to continue with our clients having a home to live in.”
Serco will extend the notice period by 21 days for six people currently subject to lock-change notices, and all further notices to other asylum seekers whose applications have been refused will be paused “whilst the law is being tested and clarified”.