Image copyright Getty Images Image caption The report considers the impact of immigration on different sectors, including agriculture

A report on UK immigration has caused a row within government because Tory ministers believed it was too pro-European, sources have told Newsnight.

The leaked Home Office report draws together evidence from 67 businesses, think tanks, unions and experts.

It concludes the influx of EU migrants has had a largely positive effect, and cites evidence suggesting they are less likely to use benefits than Britons.

The report was re-written twice. The Home Office refused to comment.

It said the report "would be published shortly".

Sceptical comments

The report, leaked to the programme, was commissioned by the coalition to look at the impact of immigration on the UK, which critics say has put too much pressure on local services.

It was due out last December, but has been delayed amid a furious row within government about its contents.

Whitehall sources have told Newsnight that the Home Office balked at the initial draft.

Image copyright Getty Images Image caption The NFU says agriculture has seen "large and positive" benefits

Home Secretary Theresa May sent it to the Home Office implementation unit, which rewrote it with more sceptical and negative comments.

The new text could not be agreed on within government and the report was eventually given to a Cabinet Office "star chamber" of civil servants to rule what stayed in and what was left out.

European elections

The 94-page text was ready in the spring, but publication was delayed, meaning it could not be used ahead of the European elections in May.

Business Secretary Vince Cable told Newsnight on Friday that the Home Office rewrite had been "propagandist".

"We disagreed with the content and thought it was propagandist rather than objective which is why we went back to the drawing board," the Liberal Democrat minister said.

"A study has now been produced that is balanced."

EU expansion

The report is a pull-together of evidence of the impact of immigration from the EU, particularly since 2004, when there was an influx with the enlargement of the union.

It quotes estimates that suggest there are 2.3m Europeans living in the UK - and up to 2.2m British citizens living in Europe.

The report's executive summary says: "The impact of the labour market is considered across a range of different sectors, including manufacturing, engineering, legal services, agriculture, hospitality, financial service and health care; and with regards to highly skilled, low skilled and regulated professions.

Image copyright Thinkstock Image caption Manufacturing was another area considered in the report

"The effects are viewed as largely positive, providing a wide range of skilled labour and opportunities for UK workers and their employers in other member states."

It acknowledges that there is "less agreement regarding low-skilled migration".

'Energetic workers'

The report notes business and industry groups, including the CBI, the British Chambers of Commerce and the City of London Corporation, together with a number of think tanks and academics, "highlighted the central importance of the principle of free movement of workers to the concept of the single market".

It does not identify benefit tourism as a big problem, citing evidence which suggests most Europeans come here to work and have a strong work ethic, and are less likely to rely on state hand-outs than Britons.

In its evidence, the National Farmers Union said: "UK agriculture and horticulture has benefitted greatly from the free movement rights of workers...the impact has been large and positive.

"It has alleviated skills shortages and provided a welcome source of energetic and motivated workers eager to undertake work that is not being filled by the resident labour force."

'Caveats needed'

David Goodhart, a director of think tank Demos, told Newsnight there should be some restrictions on the freedom of movement within the EU.

"Nobody is saying, apart from complete loonies, end freedom of movement, what we are saying is caveat it, put in qualifications," he said.

"We have this principle of non-discrimination, which means you have to treat EU citizens as if they are British citizens and that's what people don't understand - not just in Britain but across the European Union."

Image copyright Getty Images Image caption Immigration has been a major issue since the enlargement of the EU in 2004

Liberal Democrat home affairs spokesman Julian Huppert said: "I can understand why the Tories didn't want this to come out before the European elections, but I think these reports should come out promptly.

"We benefit as a country financially, socially and culturally, our food is better as a result of this migration.

"We should fix the problems that come with it, but overall we should keep with it."

Watch Nick's film on the report on Friday's Newsnight at 22:30 BST on BBC Two, except in Scotland (23:00).