Rishi Sunak has conceded his plan to stop small boats “won’t happen overnight” as he was pushed on the timescale for fulfilling his pledge.
The prime minister promised in January to end migrant Channel crossings when outlining his five priorities for his first year in office.
But asked by ConservativeHome if he would achieve that by the next general election – widely expected to take place in 2024 – Mr Sunak appeared to dodge the question.
Politics live: Boris Johnson’s downfall ‘not my doing’, claims Sunak
The government has announced controversial plans to tackle the issue in its Illegal Migration Bill, currently making its way through parliament.
The legislation includes a promise to “detain and swiftly remove” migrants and asylum seekers who enter the country illegally via the dangerous Channel crossings, and a pledge to cut the options to challenge or appeal deportation.
But critics have described the plans as “unworkable”, questioned whether they adhere to international human rights laws and raised concerns about how children will be treated.
Both Labour and the Liberal Democrats have voted against the bill in the Commons.
In the sit-down interview with the website’s editor, the PM said: “I’ve always said this is not something that is easy – it is a complicated problem where there’s no single, simple solution that will fix it – and I’ve also said it won’t happen overnight.
“I’ve been very clear about that.”
Mr Sunak added: “People should know it’s very important to me, it’s hugely important to the country that we need to fix the system, as a matter of fairness.
“It’s not fair that people are breaking the rules and coming here illegally.”
The PM also said he expected legal battles over the bill as it included measures that were “novel, untested and ambitious”.
However, he promised to fight in them in the courts, adding: “You have to expect legal challenge on these things, our job is to robustly defend them and that’s what we’ll do.”
Johnson’s downfall ‘wasn’t my doing’
Mr Sunak was also asked about his role in ousting Boris Johnson from Downing Street last summer.
Then-chancellor, he was the second cabinet minister to resign over Mr Johnson’s conduct in office, with tens of others following suit, eventually leading to Mr Johnson’s downfall.
But Mr Sunak said his predecessor’s departure “wasn’t my doing” and he had resigned for reasons “personal” to him – namely a “fundamental difference on economic policy”.
His resignation letter to Mr Johnson did mention economics, but it also said: “The public rightly expect government to be conducted properly, competently and seriously.
“I recognise this may be my last ministerial job, but I believe these standards are worth fighting for and that is why I am resigning.”
Mr Sunak urged Conservatives to move on from the infighting, saying: “I think we’ve got to, as a party, look forward.
“I said that on the first day I became prime minister, I said to the party ‘we’ve got to unite or die”.
Asked if there would ever be room for Mr Johnson in his cabinet, the now-PM said he would not comment on appointments but “we’ve got a great team and they are focused on delivering”.