And Mr Farage, unveiling his borders plan dubbed “Operation Restoring Justice”, insisted Britain must leave the European Convention on Human Rights, repeal the Human Rights Act and ignore key refugee treaties.

He declared the UK would copy Donald Trump’s mass-deportation programme by ordering Home Office Immigration Enforcement teams to carry out “large scale raids” across the country.

New “modular accommodation” will also be built to detain up to 24,000 people within 18 months of Mr Farage arriving in Downing Street, Reform said.

Addressing Zia Yusuf, Reform’s efficiency tsar, Mr Farage said: “Do we realistically think Zia, that we can deport 500,000 to 600,000 people in the lifetime of the first Parliament?”

Mr Yusuf responded “totally,” adding that there are “north of 650,000 adults without children who are in this country illegally”.

Mr Yusuf hinted Reform’s proposal to expand the immigration detention estate could allow them to deport 288,000 people per year.

These facilities would have “prefabricated two-person rooms”, canteens and “on-site medical suites”.

Migrants would not be able to leave these Secure Immigration Removal Centres.

Mr Farage defended his plans, insisting it is what “normal countries” do.

He said: “Will Border Force be seeking out people who are here illegally, possibly many of them working in the criminal economy? Yes, it’s what normal countries do all over the world.

“What sane country would allow undocumented young males to break into its country, to put them up in hotels, even get dental care? How about that?

“Most people can’t get an NHS dentist. This is not what normal countries do.”

The new ‘UK Deportation Command’ will use data from banks, the Home Office, HMRC, police, DVLA and NHS to identify every illegal migrant, Reform said.

They will then be offered £2,500 each to leave the UK during a six-month grace period.

Once the voluntary returns programme comes to an end, immigration enforcement teams will be ordered to carry out raids and arrest them.

Explaining the proposals, Mr Farage told the Daily Express: “There’s a nice way of doing this and a very tough way of doing this.

“And if people think ‘crikey, they’re breathing down my neck, they’re actually going to catch up with me and deport me, I might as well take the offer of £2,500 and a free comfortable flight back to my home country’.

“Difficult to assess just how successful that will or will not be, but if you think ‘this time next week they’re going to be knocking on my door’, I suggest quite a few people will take that up.

“It’s part of our carrot and stick approach to individuals illegally in Britain.”

Reform UK claims the plan will cost £10 billion to implement but save £7 billion currently spent on illegal migration during the first five years.

Senior party figure Mr Yusuf said that would include £4 billion for the construction and operation of detention facilities, £1.5 billion for flying people back to their home countries and £2 billion for the Foreign Office to do returns deals with countries.

He told the BBC Radio 4 Today programme that Reform would be prepared to offer money to the Taliban in order to secure an agreement with Afghanistan.

But if countries refused to take back illegal migrants, he said they would be denied visas for work, study or visits – and could even face sanctions if they continued to resist.

Diplomats will be told securing returns agreements is their “highest priority”.

Embassies in the UK will also be ordered to send “staff to assist in identifying illegal migrants”.

Mr Farage insisted the radical proposals were necessary because there was a “genuine threat to public order”.

He said: “The mood in the country around this issue is a mix between total despair and rising anger.

“And I would say this, that without action… without some trust coming back then, I fear deeply that that anger will grow.

“In fact, I think there is now, as a result of this, a genuine threat to public order, and that is the very last thing that we want.”

But Mr Farage played down fears of migrants being tortured or killed if they are deported back to countries such as Afghanistan or Iran.

He said: “The alternative, of course, is to do nothing. That’s the very clear alternative, is that we just do nothing. We just allow this problem to magnify and grow.

“We head to a point, where there, and I genuinely, I don’t want this to happen, I want our proposals to be accepted so we can prevent civil disorder from happening, but that is the direction this country is headed in. We cannot be responsible for all the sins that take place around the world. It’s just literally impossible.”

New laws will be introduced, in the Illegal Migration (Mass Deportation) Bill, to bar illegal migrants from claiming asylum and the Home Secretary will have a legal duty to remove them.

It will also be illegal to destroy your identity documents, with those caught flouting the law facing jail sentences of up to five years.

The plans will be introduced on an “emergency basis” and will last for five years before being reviewed.

The Reform leader added: “The only way we will stop the boats is by detaining and deporting absolutely anyone that comes via that route. If we do that, the boats will stop coming within days, because there will be no incentive to pay a trafficker to get into this country.

“Public trust will be restored, and we genuinely are the only party that will be trusted on this. I am the only party leader that has been clear and consistent on this issue over the course of the last five years.”

Almost 29,000 migrants have crossed the Channel so far this year, up nearly 50% compared to last year.

And some 52,000 have crossed since Sir Keir Starmer became Prime Minister.

Tory leader Kemi Badenoch accused Reform of “copying our homework” – but refused to set her own target for deportations.

She said: “We need to make sure that anyone who comes to our country illegally is deported. We have experience in government of finding some of these deportations difficult.

“That is why we had the third country deterrent, which was the Rwanda plan. Some countries will not co-operate.

“But from what Reform has announced today, they haven’t done the thinking, they’ve just copied our homework, but they don’t understand the reasons behind them.

“It’s not about the numbers, it is about making sure that we control our borders and we get all the people who are breaking our laws and coming here illegally out of the country.

“Imitation is the sincerest form of flattery, we put out a deportation Bill in May. The stuff that actually works in what he said has come from there.”

Asked whether the Government could seek deals with Afghanistan and Eritrea, the Prime Minister’s official spokesman told reporters: “We’re not going to take anything off the table in terms of striking returns agreements with countries around the world.”

The official denied Mr Farage’s claim that the country was at risk of civil disorder while stressing ministers “recognise the strength of feeling about this”.

“That’s why we’re taking serious practical action to address this issue, not just returning back to the old gimmicks, the old solutions that failed to deal with this,” Sir Keir’s spokesman said.

Labour chairwoman Ellie Reeves said: “Exactly four months ago, Zia Yusuf promised that Reform would publish a ‘comprehensive strategy’, a ‘full policy document’, and a ‘detailed plan’ for mass deportations, with a ‘year-by-year timeline’ and ‘clear targets’.

“Today, we got none of those things, nor a single answer to any of the practical, financial or ethical questions about how their plan would work.

“Nigel Farage can’t say where his detention centres will be, can’t say what will happen to women and children, and can’t say how he’ll convince hostile regimes like Iran to take people back. Only this Labour government is committed to restoring order and fairness to the asylum system.

“We’ve already returned more than 35,000 people with no right to be here – a 28% increase in returns of failed asylum seekers in just one year – and will end the use of asylum hotels by the end of the Parliament.”