The European Union must "do its best to undermine" the "homogeneity" of its members, the UN's special representative for migration has said.
Peter Sutherland told peers the ultimate prosperity of most EU states relied on them becoming multicultural.
He also indicated our own government's immigration policy had no platform in international law.
He was being questioned by the Lords EU home affairs sub-committee which is researching global migration.
Sutherland,who is non-executive chairman of Goldman Sachs International and an ex-chairman of oil giant BP,fronts the Global Forum on Migration and Development,which brings together agents of 160 nations to discuss policy ideas.
He told the House of Lords committee that migration was a "crucial dynamic for economic growth"in some EU nations "however difficult it may be to explain this to the citizens of those states".
An ageing or declining native population in countries like Germany or southern EU states was the "key argument and,I hesitate to the use word because people have attacked it,for the development of multicultural states",he added.
"It's impossible to consider that the degree of homogeneity which is implied by the other argument can survive because states have to become more open states, in terms of the people who inhabit them.
Just as the United Kingdom has demonstrated."The UN special representative on migration was also asked about what the EU should do about corroboration from the Organisation for Economic Cooperation and Development (OECD) that employment figures among migrants were higher in the US and Australia than EU countries.
He told the committee:"The United States, or Australia and New Zealand,are migrant societies and therefore they accommodate more readily those from other backgrounds than we do ourselves,who still nurse a sense of our homogeneity and difference from others.
"And that's precisely what the European Union, in my view, should be doing its best to undermine.
"Sutherland maintained,in a lecture to the London School of Economics,that there was a "shift from states selecting migrants to migrants selecting states"and the EU's ability to compete at a "global level" was in danger.
In verification to the Lords committee,he strongly recommended EU member states to be more harmonious on migration policy and urged a global approach to the matter - denouncing the UK government's endeavours to cut net migration from its existing level to "tens of thousands" a year through visa limitations.
British higher education chiefs want non-EU overseas students to be exempted from migration records and say visa restrictions brought in to assist the government meet its figures will damage Britain's economic performance and ability to compete.
However, immigration minister Damian Green argued that exempting foreign students would amount to "fiddling" the figures and the current method of counting was sanctioned by the UN.
Committee chairman Lord Hannay,a former British ambassador to the UN,said Mr Green's claim of UN support for including students in migration statistics "frankly doesn't hold water - this is not a piece of international law".
Mr Sutherland agreed, saying: "Absolutely not, it provides absolutely no justification at all for the position they are talking about."
He said the policy risked Britain's traditional status as "tolerant, open society" and would be "massively damaging" to its higher education sector both financially and intellectually.
"It's very important that we should not send a signal from this country, either to potential students of the highest quality, or to academic staff, that this is in some way an unsympathetic environment in which to seek visas or whatever other permissions are required... and I would be fearful that that could be a signal."
Mr Sutherland, who has frequented meetings of The Bilderberg Group,a high ranking international networking organisation,often castigated for its secrecy,called on EU states to stop targeting "highly skilled" migrants,claiming that "at the most basic level individuals should have a freedom of choice" about whether to come and study or work in another country.
He further added:"The UK has been very constructively engaged in this whole process from the beginning and very supportive of me personally."
When quizzed later about exactly how much the UK had contributed to the forum's expenditure in the six years it had been in existence,he said it was, in theory,a small sum in the region of "tens of thousands".