The Home Secretary will face MPs to explain the “car crash” decisions behind the chaos at a migrant holding centre.
Suella Braverman is expected to be questioned about the problems at the Manston site in Kent when she appears in the House of Commons later on Monday.
Earlier in the day, Conservative MP Sir Roger Gale described the overcrowding at the facility in his North Thanet constituency as “wholly unacceptable” and suggested it may have been allowed to happen “deliberately”.
It comes as the Channel crossing crisis deepened, amid growing concern over the conditions in which migrants are being held while waiting to be processed once they arrive in the UK, and after one of the sites in Dover was firebombed.
So far this year close to 40,000 people have made the treacherous journey from France, crossing the world’s busiest shipping lanes in dinghies and other small boats, provisional Government figures show.
Veteran backbencher Sir Roger told Sky News there are now more than 4,000 people at the Manston facility, describing the situation there as a “breach of humane conditions”.
And speaking to BBC Radio 4’s Today programme, he said: “There are simply far too many people and this situation should never have been allowed to develop, and I’m not sure that it hasn’t almost been developed deliberately.”
The Home Office is struggling to find hotel accommodation, he said, adding that he now understands that this is a policy issue and a decision was taken not to book additional hotel space.
“That’s like driving a car down a motorway, seeing the motorway clear ahead, then there’s a car crash, and then suddenly there’s a five-mile tailback.
“The car crash was the decision not to book more hotel space,” he said.
Sir Roger blamed the Home Office, under either former home secretary Priti Patel or the present incumbent Ms Braverman, of failing to book hotels, contributing to the overcrowding at the Manston migrant processing site – but Downing Street rejected the criticism.
But allies of Ms Patel said she signed off on hotel accommodation for asylum seekers whenever it was required, despite it being politically “unpalatable”.
A source close to Ms Patel told the PA news agency: “There was never any overcrowding when she was there. What would happen was if it got to the point where people were getting worried about conditions, we would sign off on more hotels.”
Despite the political difficulties, the cost to the taxpayer and the potential for a media backlash, Ms Patel agreed to hotels because “it was the right thing to do”.
Another source close to the former home secretary said it had been “business as usual” right up until the point that she resigned when Liz Truss became prime minister.
Former Home Office mandarin Sir David Normington said it could amount to another breach of the ministerial code if Ms Braverman made such a decision.
The department’s permanent secretary from 2005 to 2011 told BBC Radio 4’s World At One: “If it was deliberate, it’s a very serious matter. They mustn’t knowingly disobey or break the law.
“It’s a serious matter but we don’t know the facts and we will hear from the Home Secretary this afternoon.”
He said he was certain Ms Braverman would have been given advice by officials that she and the Home Office must abide by the law.
Dover MP Natalie Elphicke warned of “rising tensions” and called for an “entirely fresh approach” to tackle the “out of control” Channel crossings when she appeared on TalkTV, adding: “What’s been happening is simply not working.”
Chief inspector of prisons Charlie Taylor told the Today programme the Home Office needs to “get a grip” on the situation, adding: “They need to speed up the processing of migrants, they need to make suitable provisions so people can be moved off site as quickly as possible and housed in humane and decent conditions.
“The facilities are not set up for people to be staying. It’s not a residential facility. It’s a short-term holding facility which is supposed to process people through.”
Immigration minister Robert Jenrick visited Manston on Sunday after another watchdog, chief inspector of borders and immigration David Neal, told MPs he was left “speechless” by the problems at the site.
In a post on Twitter, Mr Jenrick said migrants continue to be processed “securely” in “challenging conditions”, adding: “I was hugely impressed by the staff I met, managing this intolerable situation.”
The same day police said two or three incendiary devices were thrown at a migrant processing centre in Dover and caused a fire.
The suspect, a 66-year-old man from High Wycombe, was identified and found dead at a nearby petrol station, Kent Police said.
Officers were searching a property in the Buckinghamshire market town on Monday.
Two people inside the centre at Western Jet Foil were left with minor injuries.
Although the site remained open, 700 people were moved to Manston for safety reasons.
A Reuters photographer said a man threw petrol bombs with fireworks attached before killing himself.
The attacker was described as a white man wearing a striped top, who drove up to the centre in a white Seat 4×4 vehicle, the news agency reported.
Some 468 people arrived in the UK on Sunday after crossing the Channel in eight boats.
The Ministry of Defence (MoD) also revised figures for several previous days of crossings, taking the provisional total for the year so far to 39,867.
Environment minister Mark Spencer said the UK had a “very proud record” of helping refugees and “people from other countries who are in desperate situations”, telling Sky News: “That will continue, but we need to make sure that we’re getting the right people.”
He added that the UK needs to find a way to deal with migrants “compassionately”, as he acknowledged there are “huge challenges” in the system.
Speaking on BBC Breakfast, he said there is no “silver bullet” to fix the migrant crisis, adding: “Clearly there’s more to do, but we’re making progress.”
The Prime Minister’s official spokesman said: “Obviously there is significant pressure being placed on accommodation facilities with the high number of crossings we are seeing, and it remains a significant challenge to provide the right sort of accommodation, and also indeed to fulfil our legal duty to ensure people are not made destitute.
“There is a large amount of work being done by the Home Office to secure further accommodation as we speak.”
Meanwhile, three people suspected of trying to smuggle migrants to the UK by boat have been arrested, the National Crime Agency (NCA) said.
Belgian police arrested two men, aged 34 and 44, from Basingstoke, Hampshire, on suspicion of people smuggling offences, as they arrived on the coast near Nieuwpoort, a town in the northern part of the country, at 4.30am on Sunday.
Some 12 migrants, believed to be Albanian nationals, were also detained.
A 46-year-old man was arrested by NCA officers in Aylesbury, Buckinghamshire, later the same day on suspicion of assisting unlawful immigration.
