A significant proportion of last month’s raids took place at restaurants, takeaways and cafes, the Home Office said.

It also gave examples of arrests made in vape shops in Cheshire and a grocery warehouse in south London.

Those arrested made the journey to the UK through a mix of routes, including by crossing the Channel and by overstaying legitimately-granted visas.

Home Secretary Yvette Cooper said the government was boosting enforcement to “record levels” and that immigration rules “must be respected”.

“For far too long, employers have been able to take on and exploit illegal migrants and too many people have been able to arrive and work illegally with no enforcement action ever taken,” she said.

“Not only does this create a dangerous draw for people to risk their lives by crossing the Channel in a small boat, but it results in the abuse of vulnerable people, the immigration system and our economy.”

From the start of the Labour government in July up to 31 January, 3,930 arrests were made over 5,424 visits by immigration enforcement officers.

A total of 1,090 civil penalty notices were also issued, with employers facing a fine of up to £60,000 per worker if found liable.

During the same period, four of the “biggest return flights in the UK’s history” were also carried out, the Home Office said, returning more than 800 people.

But Reform UK leader Nigel Farage described the new figures released by the government as feeble, compared with the numbers that had entered the country.

Across the 31 days of January, there were 1,098 people who arrived in the UK illegally on small boats.

The government said it launched a social media campaign in Vietnam in December and Albania in January discouraging people from making the journey to the UK.

The adverts highlight stories from migrants who entered the UK illegally “only to face debt, exploitation and a life far from what they were promised”, the Home Office said.

It comes as the government’s Border Security, Asylum and Immigration Bill is set to be debated in the House of Commons in its second reading.

The bill aims to introduce a raft of new offences and counter terrororism-style powers to clamp down on people smugglers bringing migrants across the Channel.

But Labour ministers have not provided a specific target on when a drop in small boat crossings could be expected.

The Conservatives said they had put forward an amendment to the immigration bill in a bid to include their own immigration proposals: to double how long it takes migrants to get indefinite leave to remain and, after that, require them to wait five years rather than one before they can apply for citizenship.

Philp added that “an effective removals deterrent is needed” to stop small boat crossings, something he said Labour had scrapped, a reference to the former government’s plan to send illegal migrants to Rwanda.