The Home Office has bought marquees to accommodate 2,000 migrants at disused military sites by the end of August, Sky News understands.
The tents will start to be erected over the coming weeks as part of emergency plans to deal with an expected surge of Channel crossings.
According to The Times, which first reported on the story, Border Force is predicting that the next three months will be the busiest time for the small boat journeys in a repeat of last year.
A Home Office source told the newspaper: “It’s obvious we can’t again be in a position where we’re having to spot-book expensive hotels on the fly for migrants.
“There’s nothing wrong with this kind of temporary accommodation when needed. Other countries do use it as well.”
This is not the first time the government has used marquees to house asylum seekers – several were erected at the Manston processing centre last autumn to deal with a surge of arrivals.
The tents are part of a wider strategy to seeking out new accommodation for asylum seekers to reduce the hotel bill to house them, which the government claims costs taxpayers £6m a day.
On Tuesday, the first asylum seekers are set to move on to the controversial Bibby Stockholm barge, a Whitehall source told Sky News.
An initial 50 single men are set to be moved on board the vessel that is docked in Portland Port in Dorset, with that number expected to rise to 500 in the coming months.
A record backlog and thousands of people making unauthorised crossings of the Channel have strained the system as Prime Minister Rishi Sunak battles to “stop the boats”.
But refugee charities said the use of such sites is damaging to the needs of vulnerable people, and also raised concerns for migrants’ safety.
Conservative MPs representing areas where the facilities are being established have also been worried about how local services in their constituencies will be impacted, such as police and healthcare.
A month behind schedule after undergoing repairs, the Bibby Stockholm was met by protesters as it arrived in Portland Port on Tuesday last week.
Some residents have raised concerns for their safety on the island with a population of around 13,000 and argued that it does not have the infrastructure to provide for the newcomers and those already there.
A Home Office spokeswoman said: “The Bibby Stockholm has completed a statutory inspection and refurbishment and is now berthing in Portland.
“The welfare of those in our care is of the utmost priority and the barge is now undergoing final preparations to ensure it complies with all appropriate regulations before the arrival of the first asylum seekers in the coming weeks.”