The Home Office is braced for chaos as the first removal flight to Rwanda is expected to be held by an injunction, the Mirror understands.
On Tuesday, the first group of asylum seekers will be sent on a one-way ticket more than 4,000 miles to the east African country.
Last month Priti Patel said she will "not be deterred" by "attempts to frustrate the process and delay removals".
But officials have long anticipated challenges particularly to this first flight.
Campaigners today formally launched a court bid to stop the "unlawful" removal flights, with the Public and Commercial Services Union (PCS), Care4Calais and Detention Action seeking to stop asylum seekers being forced onto the planes.
Home Office workers have told of their frustrations with the legal policy, but senior officials have urged them to use "proper channels" to raise any issues they have with the scheme, it is understood.
Officials who have issues with the scheme should consider how their colleagues feel scooping babies, and children out of Channel waters, after loved ones had made the dangerous crossings, an insider told the Mirror.
Lawyers for more than 90 migrants have already submitted legal challenges asking to stay in the UK, but officials are thought to be anticipating that the remaining 38 or so notified to be on the June 14 flight will follow suit this week.
The chief inspector of borders and immigration said the policy has not yet had a deterrent effect on the numbers of people making the perilous Channel crossing.
David Neal told the Home Affairs Committee a report on small boats crossings was sent to the Home Office in February and should have been published by April 21, but has still not been, he said.
Reports submitted should be published within eight weeks, according to an agreement with the Home Office, but this has been “routinely” breached, Mr Neal said.
Boris Johnson accepted the measure was not a “magic bullet” that will solve the crossings, but said he hoped it will be a “very considerable deterrent”.
A Home Office spokeswoman said: “As the independent chief inspector for borders and immigration made clear, he has met with Home Office ministers on a regular basis and been well served by them.”
