Britain is considering much tougher border controls, including plans for cash bonds from immigrants seeking to work or study there to make sure they don't overstay their visas.
The bonds would be required only from visitors from certain countries, but the government hasn't said which countries it sees as high risk.
Immigrants coming to Britain from countries deemed high risk may have to deposit at least £1000. This cash would then be returned as people went home, Radio New Zealand's London correspondent reports.
Deputy Prime Minister Nick Clegg says "innovative tactics" are needed to tackle the problem of immigrants arriving legally but overstaying their visas and never leaving.
Mr Clegg says there needs to be a tougher stance on immigration, but that Britain "cannot pull up the drawbridge".
He says the country's future economic prosperity depends on high quality moving to Britain, but that the system needs to be better managed.