British Deputy Prime Minister Nick Clegg called on Friday for a bail-like system to stop visitors from so-called high risk countries abusing their immigration visas.
Under the proposal, applicants would have to pay a cash deposit believed to be at least £1,000 ($1,500, 1,170 euros) which would be repaid when they leave Britain.
Clegg, the head of the Liberal Democrat party which is the junior partner in Britain's governing coalition, said he had asked the interior ministry to run a pilot scheme.
Unveiling the plans in a speech in London, Clegg said that visa overstays were one of the biggest problems facing the UK Border Agency, adding the proposed bonds would not "discriminate."
"When a visa applicant is coming from a high-risk country, in addition to satisfying the normal criteria, UKBA would be able to request a deposit -- a kind of cash guarantee," he said.
"Once the visitor leaves Britain, the bond will be repaid."
He added: "The bonds would need to be well-targeted -- so that they don't unfairly discriminate against particular groups."
He did not give any examples of what he considers a "high-risk country."
He also avoided giving a cost for the bonds but said they would be "proportionate" and "mustn't penalise legitimate visa applicants who will struggle to get hold of the money."
British media reports quoted government sources as saying the cost would be in the region of four figures.
The speech was the first that Clegg has made on immigration since the coalition formed in May 2010 and reflects how the issue is rapidly beoming central for all Britain's political parties.
The anti-immigration and anti-European Union UK Independence Party has dramatically increased its popularity in opinion polls in recent months on the back of its tough stance.
UKIP came second to the centrist Lib Dems in a recent parliamentary by-election, and beat Prime Minister David Cameron's centre-right Conservatives into third place.
Clegg did not mention UKIP by name but said that the "political mainstream has a duty to wrestle this issue away from populists and extremists."