UK Border Control
Thirty-six per cent of people said their area had \"changed for the worse\" due to immigration

A sizeable majority of Britons believe immigration has had a negative impact on the country, according to one of the largest studies yet carried out on the issue.

Of the 20,000 people polled, 60% thought immigration had brought more disadvantages than advantages to Britain. The poll was commissioned by the Conservative Party's former deputy chairman, Lord Ashcroft.

Only one in six, or 17%, believed immigration had benefited the country, according to the study, to be published on Monday and entitled Small Island: Public Opinion and The Politics of Immigration.

The research will be a cause of alarm for UK Prime Minister David Cameron, who has pledged to bring immigration under control, saying he would reduce net migration from non-EU countries to less than 100,000 a year by 2015.

"The biggest concerns were the idea of migrants claiming benefits or using public services without having contributed in return, and added pressure on schools and hospitals," Ashcroft wrote on his site, Ashcroft Polls.

Asked what would happen to the economy if immigration were to "dramatically reduce", 77% of those polled said the strain on public finances would ease, and unemployment would fall. Only 23% thought declining immigration would harm the economy.

Ashcroft's study sought to break down the prevailing cultural attitudes towards immigrants, classing respondents into seven categories.

Those showing "universal hostility" accounted for 16% of the population; those with "cultural concerns" made up 16%; those worried about "competing for jobs" numbered 14%; people alarmed at the "fight for entitlements" made up 12%; "comfortable pragmatists" numbered 22%; people showing "urban harmony" made up 9%, and those Ashcroft dubbed the "militantly multicultural" made up 10%.

Respondents were shown a list of nine measures to cut immigration, such as imposing numerical caps and language conditions, and targeting bogus students and sham marriages.

In each case, only a minority realised the measure was already law, though each policy received the backing of a majority of respondents.

'Downward pressure on pay'

In another surprise, 79% of those polled said they backed the controversial Home Office campaign to mount vans on London streets warning illegal immigrants: "Go home or face arrest". However, only 17% thought the policy would work.

Ashcroft said: "Whatever people's view of immigration itself, few think any recent government has had any real grasp of it, or that any of the parties does today."

While many Britons recognised the positive contribution immigrants can play, most remained deeply uneasy about it, according to the research.

However, almost half (49%) of respondents recognised that immigrants often did jobs that British people were unwilling to take.

Thirty-six per cent said it was harder to find work because of competition from immigrants, who also exerted downward pressure on pay.

The same proportion said the character of their area had "changed for the worse" due to immigration. Only 18% said immigration had improved their area.

Nearly a quarter believed they had been denied housing or other public services because of competition from immigrants.

Others complained about school standards falling because of the requirement for teachers to spend time helping children who do not speak English.

However, in a finding that may provide some small cheer to Ashcroft, 31% said they thought the Tories had the best approach to immigration, compared with 24% for Ukip and 23% for Labour.