Rishi Sunak has suggested he may be unable to "stop the boats" before the next general election, despite making it one of his top priorities.
The prime minister said the illegal immigration crisis cannot be solved “overnight” as it is a “complex” problem, but insisted his "plans are working".
Mr Sunak, in a speech in January, made stopping the boats one of his top five priorities ahead of next year’s likely general election but could not confirm whether he is on track to achieve that goal when asked on Monday.
When pressed, he said: “I want it to be done as soon as possible but I also want to be honest with people that it is a complex problem, there is not one simple solution and that it can’t be solved overnight and I wouldn’t be being straight with people if I said that was possible.”
More than 25,000 asylum seekers have arrived in Britain via small boats since he took office in October last year, analysis by the Labour Party has shown.
The PM said he wants to tackle illegal immigration because it is "particularly unfair on British taxpayers who are forking out millions of pounds to house illegal migrants in hotels and local communities" - but his plans to cut it have run into numerous problems.
His policy to deport illegal migrants to Rwanda still hasn't got off the ground months after becoming law due to legal challenges and plans to house asylum seekers on offshore barges and disused military bases remain stuck in the mud.
The Bibby Stockholm barge off the coast of Dorset was in use for fewer than five days before migrants were removed when traces of Legionella were found in the water supply.
And there is intense opposition to his plans to house asylum seekers at RAF Scampton, a base in Lincolnshire with historic links to the Second World War dambusters raid.
There are concerns that plans to accommodate migrants there could scupper a multi-million pound investment aiming to purchase and redevelop the site.
Asked about the risk posed, Mr Sunak said: “Of course the Home Office and other authorities are in dialogue with all local partners to work through all the outstanding issues and questions.
“But more fundamentally we have got to stop the boats. That is why it is one of my five priorities. The current system is unsustainable and it is unfair. The best way to reduce pressure on local communities is to stop the number of people coming here in the first place.
“We can’t have a situation where British taxpayers are forking out millions of pounds a day to house illegal migrants in hotels in local communities. We have got to find alternatives to that. That is what some of our large sites and the new barge are about.”
Downing Street said the government aims to return people to the Bibby Stockholm barge “as soon as possible”, but would not provide a timeframe.
Asked whether ministers had received the results of tests following the discovery of Legionella bacteria, the prime minister’s official spokesman told reporters: “The Home Office are still awaiting the results of the further tests.
“As I said they want to re-embark people as soon as possible once those tests have been completed.”
He added: “We continue to work closely with the contractors on this to make sure that the accommodation is appropriate and we have all the tests in place.”
The PM said the number of crossings was down in 2023 on the previous year, suggesting his “plan” was working, but added: “I am not complacent. I never said this would be easy, I never said it could be fixed overnight.
“We are going to attack it from every angle and not stop until we are done.”
Home Office figures up to Friday suggest that almost 17,500 people have arrived in the UK on a small boat this year, on top of 7,600 people who crossed the English Channel between October 25, when the PM entered Downing Street and December 31.
Labour's shadow immigration minister Stephen Kinnock said last week that Mr Sunak had “fundamentally failed to get a grip” on illegal immigration to the UK.
Mr Kinnock said: “The Conservatives have allowed criminal smuggling gangs to take hold on Britain’s borders and Tory incompetence is risking our national security, putting lives at risk, and pounding the public purse for millions every day.
“Rishi Sunak has fundamentally failed to get a grip and crossings are rocketing on his watch.
“It’s time for a different approach. The prime minister must now back Labour’s plan to stop the dangerous Channel crossings by going after the criminal gangs, by securing a returns deal with Europe, and by clearing the asylum backlog which is costing the taxpayer £6 million a day.”