Business Secretary Vince Cable has rubbished plans to reduce net immigration saying it would do "enormous damage" to the UK.
The Liberal Democrat said meeting a pledge to reduce immigration to under 100,000, was an "unattainable" target unless areas that benefited Britain, such as international student numbers, were hit. It wasn't part of the Coalition agreement.
In an interview for parliamentary journal The House Cable said: "It isn't Government policy, it is Conservative policy. And it's also not true because that policy purely relates to non-EU people.
"We have obviously no control over the European Union and that is actually where much of the movement comes. And a lot of the public anxiety which is experienced in by-elections and elsewhere has actually been about people from Eastern Europe.
"Now, you can argue whether that's a good thing or a bad thing but it's got nothing to do with the non-EU, which is the area which is controlled by government.
"The reducing to under 100,000 is not Government policy and it would be unattainable without, if it was attainable enormous damage would be done, notably through overseas students, which is one of the biggest components, actually."
Home Secretary Theresa May wants to reduce non-EU migration to the tens of thousands by 2015. Figures released by the Office for National Statistics last month show a net flow of 163,000 migrants came to the UK in the year to June 2012, down from 247,000 in the previous year.
But MPs on the Business, Innovation and Skills Committee have criticised the Government for refusing to take international students out of the target.
Asked if he believed the pledge would be hit by the end of the parliament, he replied: "The argument that Government can somehow deliver this, when you think about the logic of it: net immigration means reducing the number of people coming in or increasing the number of British people emigrating. Is that the policy objective? I don't know."
He added: "The problem we have in many of these emerging markets with prospective overseas students, it's not the system, it's what they've read in the newspapers of the system, it's a perception issue, they've read 'Britain is Closed' and they don't come here or they don't apply, particularly in India. Less so in China where they don't have independent newspapers to read.
"We want overseas students, they are good for us, they are not bad for us. They bring in lots of money. We want to have lots of visitors from all over the world coming here without hassle, an easy flexible visa system and we have lots of highly specialised people in engineers, top managers who we need in our companies and they've got to be able to come and go freely otherwise we are not going to be able to compete internationally. So I do have to keep banging the drum for that."
Asked about the government's immigration policy at a regular Westminster briefing, the Prime Minister's official spokesman said: "The government's policy, it's unchanged."
In the wide-ranging interview, Mr Cable said he would stand for election again in 2015, pointing out he was in the company of great prime ministers by continuing in politics at an older age.
Asked if Gladstone was his role model: "Yes, well, he became Prime Minister when he was over 80, didn't he? I think Churchill was over 70, wasn't he?"
"Talking of role models, Deng Xiaoping totally transformed China in the last century. I think he was 80 when he took over. And he survived the Long March."