British Prime Minister Rishi Sunak on Wednesday defended his new “Stop the Boats” crackdown on migrants making unsafe journeys across the English Channel to illegally cross over into the UK from neighbouring France.

Sunak was challenged during the weekly Prime Minister's Questions (PMQs) in the House of Commons by the Opposition over the feasibility of the Illegal Migration Bill tabled in Parliament, which would see all those arriving illegally on such “small boats” either returned to their home country or another “safe third country".

Additionally, anyone found to have entered the country illegally blocked from returning or claiming British citizenship in future.

"Stopping the boats is not just my priority, it's the people's priority," Sunak told MPs.

"Our position is clear, if you arrive here illegally you will not be able to claim asylum," he said.

Opposition Labour Party Leader Keir Starmer countered that the government's proposals as just "more talk, more gimmicks, more promises to be broken". But Sunak countered that while he has a clear plan to stop people coming in the first place, Labour has no plan because it does not want to tackle the problem.

"People must know that if they come here illegally it will result in their detention and swift removal. Once this happens – and they know it will happen – they will not come, and the boats will stop,” said Sunak.

"We will detain those who come here illegally and then remove them in weeks, either to their own country if it is safe to do so, or to a safe third country like Rwanda. And once you are removed, you will be banned — as you are in America and Australia — from ever re-entering our country. This is how we will break the business model of the people smugglers; this is how we will take back control of our borders,” he said.

The British Indian leader has insisted that the new measures are tough but “necessary and fair”.

The move follows Indian-origin Home Secretary Suella Braverman laying out the government's proposals in the Commons on Tuesday, in an attempt to curb an expected 40,000 people crossing the English Channel this year – a figure that is significantly higher than the few hundreds making the dangerous crossings a few years ago.

"It has to stop. By bringing in new laws, I am making it absolutely clear that the only route to the UK is a safe and legal route," said Braverman.

If you come here illegally, you won’t be able to claim asylum or build a life here. You will not be allowed to stay. You will be returned home if safe, or to a safe third country like Rwanda. It’s the only way to prevent people risking their lives and paying criminals thousands of pounds to get here,” the minister added.

However, Labour's shadow home secretary, Yvette Cooper, challenged her strategy to say the plans would make "the problems even worse, and make it more chaotic" and "more lives put at risk". She also accused government ministers of being "irresponsible" in their language and argued they had focused on "gimmicks" and "rhetoric".

Meanwhile, the United Nations refugee agency has described the moves as "very concerning" and would block even those with a compelling claim. The UN High Commissioner for Refugees’ (UNHCR) representative to the UK, Vicky Tennant, told the BBC that the measure would break international law.

"We believe it's a clear breach of the Refugee Convention, and remember even people with very compelling claims will simply not have the opportunity to put these forward," she said.

The Refugee Convention, first agreed in 1951, is a multilateral treaty that sets out who qualifies as a refugee and the obligations of signatory states to protect them.

The UK government has insisted the new measures are "lawful, proportionate and compassionate".

Under the new law, it will be the Home Secretary's duty “to remove" those entering the UK via illegal routes. This will take legal precedence over someone's right to claim asylum – although there will be exemptions for under-18s, those with serious medical conditions, and some "at real risk of serious and irreversible harm".

Any other asylum claims will be heard remotely after removal. The bill also allows for the detention of illegal arrivals without bail or judicial review within the first 28 days of detention, until they can be removed.

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