Forum for Republican candidates bars Ron Paul, currently polling second in Iowa, for his 'extreme' views on Israel

The Republican Jewish Coalition has barred Ron Paul, one of the party's leading presidential contenders, from its forum for the candidates on Wednesday because of his "misguided and extreme views" on Israel.

Paul, who consistently ranks among the favourites in polls of Republican primary voters despite strong libertarian views that have alienated many in his own party, has rankled Israel's supporters by advocating an end to US aid to the Jewish state. He is also strongly opposed to military action against Iran's nuclear programme and has drawn attention to Israel's own atomic weapons which it does not officially acknowledge.

The RJC director, Matt Brooks, said Paul was excluded for those and other views.

"He's just so far outside of the mainstream of the Republican party and this organisation," he told CBS.

Earlier this year, Paul wrote to congressional colleagues urging them to cut billions of dollars of aid to Israel, Egypt, Pakistan and Jordan. He said that the US "borrowing money from China – or printing it out of thin air – to hand out overseas in attempt to purchase friends has been a failing foreign policy".

At a Republican candidates debate last month, Paul said the US should not back Israel if it attacks Iran's nuclear sites.

"We don't even have a treaty with Israel. Why do we have this automatic commitment that we're going to send our kids and send our money endlessly to Israel? So I think they're quite capable of taking care of themselves," he said.

Critics have described Paul as isolationist and compared him to appeasers of the Nazis. Donald Trump, the billionaire developer who is hosting a Republican debate later this month, took a swipe at Paul on Fox News on Monday: "He doesn't care if Iran gets a nuclear weapon that could wipe out Israel."

Paul has previously fallen afoul of the RJC for being strongly critical of the pro-Israel lobby in Washington and for comments likening conditions in Gaza to a concentration camp in saying that the US should not support the blockade of the territory.

"I think it is absolutely wrong to prevent people who are starving and having problems, almost like in concentration camps, and saying: yes, we endorse this whole concept that we can't allow ships to go in their in a humanitarian way," he said. "I think this would be a perfect opportunity to argue the case: Israel, if you want to do this, you're on your own. We're not backing you up."

Brooks previously criticised Paul when he launched his presidential campaign earlier this year saying his views are "far outside of the Republican mainstream" and that he has "espoused a dangerous isolationist vision for the US and our role in the world".

"He has been a virulent and harsh critic of Israel during his tenure in Congress. Most recently Paul gave an interview in which he voiced his objection to the recent killing of Osama Bin Laden," he said.

But Paul has also said that Israel is a "close friend" of the US, and that it should be free to decide its own position in negotiations with the Palesitnians without pressure from Washington.

Paul has also upset many in his own party by saying that the US brought the 9/11 attacks on itself through its actions in the Middle East and by maintaining military bases in countries such as Saudi Arabia. He advocates severely cutting the US military budget and bringing almost all the country's forces home.

The coalition's barring of Paul comes as the Republicans attempt to shake off the damage done by a question about foreign aid at a candidates debate last month in which three of the leading contenders – Mitt Romney, Newt Gingrich and Rick Perry – said they wanted to scrap existing foreign aid commitments and then have each country justify assistance, including Israel. Although the candidates swiftly said after the debate that they expected aid to Israel to continue, the damage was done among some of the Jewish state's supporters.

The Paul campaign did not immediately respond to a request for comment.