Immigration Minister Mark Harper had "no choice" but to resign, Ukip leader Nigel Farage said, after discovering that Mr Harper's cleaner was in the UK illegally.
Mr Farage said: "After all he was the guy behind what I thought were those rather unpleasant vans driving around London saying 'if you're an illegal the time has come to go home', so he had no choice,"
"It rather sums up the very bad few weeks the Government has had with the question of immigration and what a mess the whole thing is."
More top news
Five men died in the water at Camber Sands on the hottest day of the year - and a sixth is believed to be missing.
Colombia's government and the country's biggest rebel group have reached an historic peace deal, ending half a century of hostilities.
Two members of the cabin crew were booted off the flight after a heated row over unpacking the water bottles.