Nigel Farage will today pledge to deport 400,000 people who have been granted asylum in the UK, to reverse what Reform is calling “an invasion of Britain”. The historic promise, set to form a centrepiece of Reform’s general election campaign, will provoke a furious reaction from left-wingers and human rights campaigners.

But Reform UK leader Mr Farage and his home affairs spokesman, Zia Yusuf, will argue that people who came to the UK illegally, or overstayed their visa, must not be allowed to remain. The party has already said that nobody who breaks immigration rules in the future will be allowed to stay, if Reform wins power. The new announcement applies to people who have already been granted asylum.

Mr Farage will announce plans to review all asylum grants going back five years. Those who entered the country illegally, or arrived with a valid visa but then overstayed before claiming asylum, will be forced to go, along with any dependents. People granted asylum whose country of origin is now considered safe will also have to leave.

They will be given a chance to depart voluntarily, and those who remain will be deported under what Reform is calling Operation Restoring Justice.

The party estimates that this will apply to 400,000 people in total, if they form a government after a 2029 election.

Mr Yusuf said: “For years, Tory and Labour governments have presided over an invasion of Britain. They have effectively operated an open borders policy. Instead of upholding the law, they have rewarded those who broke it by entering Britain illegally.

“Reform will reverse this. Today we announce that a Reform government will review the previous five years of asylum grants, and anyone who broke into the country illegally or overstayed on another visa will be stripped of their status and deported.

“We will do what it takes to restore justice in Britain.”

Individuals on Ukrainian schemes and British National (Overseas) visas such as citizens from Hong Kong will not be affected.

Prime Minister Sir Keir Starmer has vowed to “smash the gangs” responsible for trafficking migrants across the Channel but 602 people on nine boats arrived in Dover on Saturday, the second busiest day for crossings this year.

It brought the number who have arrived in the UK so far this year to more than 6,000.

The UK has paid £478 million to France to fund attempts to stop departures, including by stepping up patrols along the French coast. An additional payment of £16.2 million was agreed last month.

But gangs charging as much as £5,000 for a place on a dinghy are making more departures from Belgium instead, in a tactic designed to evade law enforcement.

Prime Minister Sir Keir Starmer and French President Emmanuel Macron vowed to keep up the fight against illegal immigration in a conversation last week. A No 10 spokesperson said: “The Prime Minister and president agreed on the need to continue momentum to drive down illegal crossings between France and the UK, and tackle the problem upstream working with international partners.”