The Labour party has said that the resignation of Immigration Minister Mark Harper demonstrates the complexity of immigration checks for landlords and employers.
Mr Harper resigned after discovering that his cleaner was in Britain illegally, although Downing Street said there was nothing to suggest that he knowingly employed an illegal immigrant.
"This information about Mark Harper’s employee does put him in a difficult position," Mr Hanson said.
"Perhaps once again the government need to think very carefully about how they approach this issue, as it is clear there are limits to the effectiveness of relying on employer and landlord checks to address illegal immigration."
More top news
The President's announcement on climate change is yet another attempt at securing an elusive climate change legacy.
Two cranes have collapsed during a bridge building operation onto housing in Holland, seriously injuring at least 20 people, reports say.
About 130,000 litres of fake vodka have been seized from an illegal booze factory, the tax office said.