In a speech on immigration on Saturday, Nick Clegg suggested those from from “high risk countries”, including students, would pay £1,000 cash deposits on entry to the UK, which would be refunded as long as they left the country on time.

“I think it’s incredibly worrying that we’re constantly seeing new announcements by all three political parties on immigration”

He said migrants made a huge contribution but promised “zero tolerance” of abuses. Noting that the policy had been floated by the previous government, he said: “If we get this right, there is no reason why this cannot make the system work more efficiently.”

However, Keith Vaz, former Labour minister and chairman of the Home Affairs Select Committee, said the idea was “unworkable, impractical and also discriminatory”— and had been poorly received in India when he first proposed it in the 1990s.

He added that the bond in itself would not be enough of a deterrent and only sour relations with other countries.

“We have to choose the countries we want to target,” he told the BBC’s Daily Politics. “They are going to be very angry. They are likely to retaliate against Britain.”

Clegg’s speech reflects tougher rhetoric on immigration from all three major political parties as they face pressure from the rise of the UK Independence Party. UKIP, which stole third place in the recent Eastleigh by-election, calls for radically tougher immigration controls and now commands 17% in national opinions polls – above the Liberal Democrats and just 11 percentage points below the Conservatives.

A speech from the Prime Minister David Cameron today set out a range of proposals to crack down on immigrants from within the European Economic Area – the 27-nation European Union plus Norway, Iceland and Liechtenstein – abusing the welfare system. In it he suggested all temporary residents from the EEA, including students, would soon have to pay private health insurance to access Britain’s free health system, the NHS.

The Labour leader Ed Miliband has also proposed a tougher line in recent months, after claiming last June that there was too much immigration from new European Union states when his party was in power.

Daniel Stevens, International Officer for the National Union of Students, told The PIE News: “I think it’s an incredibly worrying sign that we’re constantly seeing new announcements by all three political parties on immigration. The impact on international students is the persistently damaging rhetoric that causes an atmosphere of perceived hostility.”

“They are the ones who bring earnings and growth and prosperity and what we need now is to see this reflected in policy”

He added: “One simply has to put Canadian and British immigration-related press releases side by side to realise how different the realty is in terms of Government policy and the subsequent trickle-down effect that can have on international student policy.”

Dominic Scott, Chief Executive of UKCISA, said that the EEA focus of Cameron’s speech was at least an improvement on previous  policies targeting non-EU students.

“It appears that for once the Prime Minister’s remarks were not mainly aimed at international students and it is quite clear now that most concerns on immigration focus on EU migrants with students, as we have said for years, being largely irrelevant to the vast majority of British voters,” he said.

“They are the ones who bring earnings and growth and prosperity and what we need now is to see this reflected in policy, as in so many ways students are irrelevant to the immigration debate.”