James Cleverly has claimed his parliamentary aide was making a “counterintuitive statement” for dramatic effect when he described the Rwanda policy as “crap”.

The Home Secretary said James Sunderland was supportive of the policy and its deterrent effect, but was making a point to grab the attention of his audience.

In a recording passed to the BBC, Mr Sunderland is heard telling a private event his thoughts on the plan to send asylum seekers on a one-way trip to the African country.

Mr Sunderland, who is standing for re-election in Bracknell, said: “The policy is crap, OK? It’s crap.”

According to the BBC, in the recording from a Young Conservatives event in April Mr Sunderland continued by defending the plan and saying it would deter migrants from attempting to cross the Channel.

Saying the “effect of the policy” was what mattered, he added: “There is no doubt at all that when those first flights take off that it will send such a shockwave across the Channel that the gangs will stop.”

Mr Cleverly told Sky News’ Sunday Morning with Trevor Phillips that Mr Sunderland was “very supportive” of the policy.

“I’ve had a conversation with him and I’ve also heard the recording. And it’s clear what he’s doing is he’s putting forward a very counterintuitive statement to grab the attention of the audience,” Mr Cleverly said.

“If you actually listen to what he then went on to say, he was saying that the impact, the effect, is what matters.”

The Home Secretary added: “He did it clearly for dramatic effect to grab the attention of the audience.

“But he is – and it’s clear in the recording – completely supportive of the deterrent effect that the Rwanda policy has.”

In the recording, Mr Sunderland also criticised colleagues for “courting controversy”, naming then MPs and current Conservative candidates Jonathan Gullis and Brendan Clarke-Smith as those who “polarise opinion”, alongside former Tory Lee Anderson, who switched to Reform in March.

Mr Sunderland told the BBC he was “disappointed” at being recorded at a private event.

He said: “I was talking about the response to the policy. The policy itself is not the be all and end all, but part of a wider response.”

In response to the criticism of colleagues, he said he was answering a question about resignations from party posts by saying “unnecessary rhetoric and division in public life” was unnecessary.

Liberal Democrat home affairs spokesman Alistair Carmichael said: “The Rwanda policy is an immoral, costly gimmick and everyone, including top Conservatives, knows it.

“Rishi Sunak has poured hundreds of millions into his failing vanity project – it’s a disastrous waste of money.

“Liberal Democrats would smash these gangs putting lives at risk and fix our immigration system.”

Shadow education secretary Bridget Phillipson told the BBC’s Sunday with Laura Kuenssberg: “If the Conservatives thought that this plan around Rwanda was going to work, that they were going to get flights off the ground, I’m not sure they would have called the election for now.”

Mr Cleverly, writing for the Sunday Telegraph, claimed the UK risks being required to take “100,000 more illegal migrants” into the country from the European Union if Labour joined a quota scheme for migration with the bloc.

Ms Phillipson, told there may well be a quid pro quo of accepting quotas of migrants from the EU and asked to rule it out, replied to the BBC: “What we’ve seen today is the Conservatives have been making all kinds of claims about this – the usual desperate lies that we’ve seen right throughout this campaign.”

She added: “We do need to make sure we get to a position where we have better returns agreements and, for example, that would be around family reunification, but that would be subject to negotiation.

“We will not be part of any EU quota system and any suggestion of that kind is completely wrong.”

Meanwhile, the number of people crossing the English Channel in small boats since Rishi Sunak entered No 10 is expected to pass 50,000 soon after further activity was reported on the water on Sunday.

The latest Home Office figures suggest 49,707 people have made the crossing since Mr Sunak became Prime Minister.

Shadow paymaster general Jonathan Ashworth said: “Whatever else happens in this election campaign, Rishi Sunak will always be known as the Prime Minister who broke his promises to Britain.

“He pledged to stop the boats, but has seen 50,000 people make the crossing on his watch, is currently presiding over the worst year ever for small boat arrivals, and has the Home Secretary’s closest parliamentary aide now dismissing his Rwanda policy as ‘crap’.”