Immigration rhetoric putting off overseas students - peers
The government's "overblown rhetoric" on efforts to bring down immigration has contributed to a drop in students doing technology, engineering and maths courses at UK universities, peers say.
The Lords Science and Technology Committee said "inflammatory" media coverage and people's "perception of the rules" were a deterrent.
The UK was seen as an "unwelcoming destination", it added.
But the government said the peers' report lacked "clear evidence".
It said it was controlling immigration while "attracting the brightest and the best".
Prime Minister David Cameron has said he wants to get the level of net migration - the difference between the number of people coming in and leaving - down to "tens of thousands" by 2015.
Since April 2012, foreign students have faced stricter visa regulations, in an effort to cut down on bogus immigrants.
But the government stresses that there is no cap on the number of people legitimately coming to the UK to study.
The number of students studying science, technology and maths (Stem) subjects - including courses such as medicine, architecture and computer science - fell by more than 10% from 58,815 in 2010-11 to 52,905 in 2012-13.
The committee's report said: "It was put to us on numerous occasions that it was not the immigration rules as such that were deterring students, but their perception of the rules as a result of overblown rhetoric from ministers and sometimes inflammatory media coverage in the UK and in overseas countries."
It added: "The UK was seen as a destination that was unwelcoming to some international students."
But the report said the evidence "pointed to difficulties beyond simply those of perception", with the "complexity and instability" of the immigration rules also posing problems.
"The UK's offer to prospective international students remains a good one; it is founded on academic excellence, but it has been diminished by perceived and real barriers so that the overall offer is not as competitive as it needs to be," the peers said.
Ministers have set out plans to increase the number of international students by up to 20% over the next five years.
But the committee said: "The government maintain that they emphatically welcome international students, unfortunately, elements of policy and perception are working against this admirable aim.
"The view within government that current policies are working well is disconnected from the concerns we repeatedly heard."
But a Home Office spokesman said: "We do not accept that the UK's immigration rules are deterring international students and there is no clear evidence in the report to support that argument - where some courses and countries have seen falling numbers, other countries and courses are on the rise."
He said the UK remained "the second most popular destination for international higher education students", with enrolments from "key markets", such as China, Malaysia and Hong Kong increasing.
The spokesman added: "The student visa system we inherited was weak and open to widespread abuse. We are controlling immigration while still attracting the brightest and the best - as the published figures show."