More than 20,000 migrants have arrived in the UK after crossing the English Channel since Sir Keir Starmer became Prime Minister.

It is understood official Home Office figures due out on Monday will show that the total has topped 20,000 crossings since Sir Keir entered Number 10 in July.

Before the weekend the total number of crossings stood at 19,988 since Sir Keir had become PM, but it is thought that the arrivals due to be added would take the total over the milestone figure.

Some 50,637 arrivals were recorded during Rishi Sunak’s premiership, which began on October 25 2022.

It took around eight-and-a-half months for migrant crossings to top 20,000 after Mr Sunak became prime minister.

His tenure began in the autumn, meaning his first few months in power coincided with winter weather conditions when typically fewer crossings take place.

By contrast, Sir Keir took on the role in the middle of the summer period when crossings are usually at their most numerous and frequent amid spells of better weather.

It took about five months for migrant crossings to hit 20,000 after he came to power.

A Labour source told the PA news agency: “Robert Jenrick told the truth last week. He said the Tory Party’s ‘handling of immigration let the country down badly’, and ‘caused immense and lasting harm’.

“He said the public had a ‘right to be furious’ and that the Conservative Party should feel ashamed. We will not repeat those same mistakes, and nor will we let the Tories forget them.”

The source added: “The country voted for change. The Home Secretary went to Iraq last week to sign a world-first deal on tackling these evil smuggling gangs that facilitate these Channel crossings.

“The Tories’ gimmicks like Rwanda didn’t work, the former immigration minister, Robert Jenrick, admitted that. We have to smash the gangs, secure our borders, tackling this problem upstream.”

The last crossings recorded in the Home Office data were on November 16 when 425 people arrived, and November 15 when 237 people arrived.

Before then, there had not been any since November 10 when 209 people arrived in one day.

It comes after the Prime Minister announced a major overhaul of the immigration system and accused the Conservatives of running “a one-nation experiment in open borders” amid concerns over the number of people legally arriving in the UK.

Sir Keir said his Government had inherited an “utter mess” in the Home Office and new Tory leader Kemi Badenoch admitted her party had failed on migration.

The Prime Minister told a Downing Street press conference: “Let me say directly to the people watching: where the last government failed you, this one will not. They drove immigration numbers up. We will get them down.”

Recent figures showed the cost of the UK’s asylum system has risen to £5 billion, the highest level of Home Office spending on record and up by more than a third in a year.

Other data showed 35,651 asylum seekers were being housed in UK hotels at the end of September, up more than 6,000 since the end of June, signalling the first quarterly rise for a year.

Meanwhile, Home Secretary Yvette Cooper announced a “landmark” deal with Iraq, intended to crack down on people-smuggling and boost border security.

The Prime Minister has put international co-operation with law enforcement agencies in Europe at the heart of his bid to cut the number of arrivals.

He previously said his Government “inherited a very bad position” with record numbers of migrants in the first half of the year “because the entire focus until we had the election was on a gimmick, the Rwanda gimmick, and not enough attention was on taking down the gangs that are running this vile trade”.

But “if the boats and the engines aren’t available, it obviously makes it much more difficult for these crossings to be made”.

His comments came after he vowed to “treat people smugglers like terrorists” as he announced extra cash for his Border Security Command.

Ms Cooper has so far not committed to a target or timeframe for curbing Channel crossings but pledged the Government will “try and make progress as rapidly as possible”.

The National Crime Agency has said it is leading around 70 live investigations into organised immigration crime or human trafficking.

Some 50 people have died while trying to cross the Channel this year, according to incidents recorded by the French coastguard, in what is considered the deadliest year since the crisis unfolded.

The International Organisation for Migration (IOM) has also reported several more migrant deaths believed to be linked to crossing attempts so far in 2024.