The report, drawn up by Tory officials in 2007, concluded that the Conservatives should be wary of a link with the Polish Law and Justice party (PiS) because its members were on the far right, with some tending towards antisemitism.
Two years later, however, the concerns raised in the internal document were brushed aside as Cameron split from Europe's mainstream centre-right group to form a new alliance with Law and Justice and other right-of-centre parties in other member states.
One of the Law and Justice MEPs, Michal Kaminski, who has been accused of blatant homophobia and supporting antisemitic causes in his past, was appointed to lead the group. The party was in mourning yesterday after one of its most senior figures, the Polish president, Lech Kaczynski, was killed in a plane crash in western Russia.
Kaminski denies being a homophobe, despite having defended public remarks in which he described gay men as "poofs".
Ten days ago the Observer asked the Tories to confirm the report's existence, and for an explanation of why its findings were not acted on, but the party has not responded.
The revelation that the Tory leadership received internal advice from its staff to reject Law and Justice will raise new questions as to how William Hague, the shadow foreign secretary, and Cameron have been able to claim their new partners are from Europe's "mainstream".
A former Polish MEP, Jozef Pinior, said he had been shown a summary version of the report in 2007 by "Conservative friends" in the parliament. It contained advice "not to break away from the European Peoples party (the mainstream centre-right group) ... it made clear it was too politically dangerous", he said.
Edward McMillan-Scott, the former Tory MEP who was expelled from the party after raising concerns about Kaminski and Law and Justice, said: "I knew the report existed but I never saw it. I took my party at its word at the time when it said that it would not sign up with those from the wild fringes of European politics. But I was wrong."
Another senior EU source said: "We know about the report. The main piece of work runs to 200 pages or so. It was thorough. Serious concerns were raised about Law and Justice and several other potential allies at that time."
The Guardian
