Ukip MEP Gerard Batten in action in Strasbourg. Photograph: Jean-Marc Loos/Reuters/Corbis
A Ukip MEP who is under fire over his remarks about Islam also suggested banning halal and kosher slaughter of animals and outlawing the legal recognition of Islamic banking.
In 2011 Gerard Batten was the author of a four-page paper entitled "Confidential draft – Dismantling Multiculturalism", which was billed as a policy discussion document with "suggested policies that could be adopted by political parties and governments".
It was sent to members of Christian Concern, a group that believes that abortion should be illegal and homosexuality is a sin. Batten said he held a meeting with them and sent a document to some of their members.
The paper claims that multiculturalism has failed and offers a doom-laden warning about the threat of radical Muslims. "Islamic fundamentalism is the cuckoo in the western multicultural nest. We can either address it now or be destroyed by it in the course of time," he wrote.
A future government should also ban the religious slaughter of animals, he suggests. "Repeal the act of parliament that gives exception for ritual slaughter for religious reasons. These are outmoded and barbaric practices that have no place in the 21st century or in the light of humane animal welfare policies," he wrote.
Batten also suggested that Ukip might consider dropping any laws that recognise Islamic banking: "Repeal the Act (???) that gives official recognition to Islamic banking." There are no references to Islamic finance in UK legislation, according to the Treasury.
On Tuesday, the Guardian reported that Batten supported the creation of a code of conduct for British Muslims and argued for a ban on new mosques in Britain. Batten is an MEP representing London, and is top of the party's list for the city in the elections in May.
On Wednesday, before details of Batten's latest policy position emerged, the Ukip leader, Nigel Farage, was forced to disown the London MEP's call for a "charter of Muslim understanding".
Farage said: "This was a private publication from Gerard Batten in 2006 and its contents are not and never have been Ukip policy. No such policy proposals would have been accepted by Ukip in any case. Ukip believes in treating people equally."
The party is keen to shake off its image as a disparate group of eccentrics and to approach May's European elections as a serious electoral force.
David Cameron described them as "a bunch of fruitcakes, loonies and closet racists". Batten described the 2011 document as an "off-the-top-of-my-head draft of a document which was for a policy discussion which so far has never been published". He said it was "a rough draft which I would like to publish in due course but it's not one of my priorities at the moment. You can't hold me to anything in it."
He declined to say whether he supported banning religious slaughter, but added that he made those suggestions to ensure they had a lively discussion. "If you put a few off the wall things down it makes the conversation interesting, doesn't it?" he said. In the paper, under the heading "Policy suggestions", Batten also wrote that the government should consider dropping the display of languages such as Hindi, Urdu or Polish from public institutions.
"There must be one language used in national and political institutions and publicly funded places (excluding historical differences such a Welsh in Wales or Gaelic in Scotland). In England only English must be displayed in public buildings such as local and national government offices, universities, colleges, schools, hospitals, clinics etc" he wrote.