A senior Cabinet minister has rejected claims that Britain's EU membership has been responsible for "unacceptable waves of migration".
Kenneth Clarke told the Financial Times that the migrants from other parts of the European Union had made "a positive contribution to our economy" and helped create "a far more exciting and healthier" society.
His comments appeared to contradict Prime Minister David Cameron's warning last month that there must be no repeat of the "vast migrations" seen after eight eastern European countries - known as the A8 countries - joined the EU in 2004.
But Downing Street gave a measured response to Mr Clarke's remarks, pointing out that the Prime Minister had made clear he recognised the "positive contribution" made by migrants to the UK, and declining to respond to reporters' questions over whether he regarded recent levels of migration as "unacceptable".
Mr Clarke, who is serving the PM as trade envoy and minister without portfolio, told the FT: "I just don't think it's true that the European Union is responsible for unacceptable waves of migration.
"The idea that you can have some fundamental debate that somehow stops all these foreigners coming here is rather typical right-wing nationalist escapism, I think."
Mr Cameron moved to introduce a new three-month ban on new immigrants claiming benefits, amid a wave of concern about the lifting of work restrictions on Romanians and Bulgarians on January 1.
He last month warned the other 27 EU leaders at a Brussels summit that the UK could veto future accessions of new member states unless stricter "freedom of movement" controls were imposed.
And last weekend, Work and Pensions Secretary Iain Duncan Smith upped the ante by saying that he would like EU immigrants to have to wait for up to two years to claim benefits, while Labour's Chuka Umunna said there was still too much low-skill migration within Europe.
Asked whether Mr Cameron agreed with Mr Clarke that levels of migration had not been "unacceptable", the PM's official spokesman told a Westminster media briefing: "Immigration in the decade up to 2010 was allowed to be out of control. The Prime Minister has been very clear about that. It was too high, the Prime Minister was very clear about that.
"One of the mistakes that was made in the decade before 2010 was not imposing transitional controls at the time of the A8 accession."
But the spokesman added that, in a speech last March, Mr Cameron had recognised "the very positive contribution that we have seen communities coming to the UK have made in the past" and made clear that the UK wants to continue to attract "the brightest and the best".
"You can say all these things while still saying that immigration in the decade up to 2010 was allowed to get out of control," he said.