John McCain, the presumptive Republican presidential nominee, has been called upon to renounce a church leader he considers his spiritual guide for urging a Christian war to destroy the “false religion” of Islam.

A number of prominent US weblogs demanded he reject the support of Reverend Rod Parsley, of the World Harvest Church of Columbus, an influential televangelist and political figure who campaigned alongside him in the run up to the Ohio primary.

On February 26, a week before the Ohio vote, Mr McCain appeared at a campaign rally in Cincinnati with the evangelical pastor, who praised the candidate as a “strong, true, consistent conservative”. With Mike Huckabee, a Baptist preacher, then continuing to snap at his heels, Mr Parsley’s endorsement was a boon to Mr McCain’s efforts to knock out his last remaining challenger and win over social conservatives. Standing side-by-side with the minister, Mr McCain hailed him as a “spiritual guide”.

Since then, the writings of Mr Parsley have attracted attention from political commentators. Several have noted that Mr McCain's Democratic rival, Barack Obama, was forced to publicly denounce and reject the support of Louis Farrakhan, leader of the Nation of Islam, after he received unsolicited praise from the controversial figure.

The leader of a 12,000-member megachurch, Mr Parsley has written several books detailing his fundamentalist views, including the 2005 Silent No More. In this contentious work, Mr Parsley castigates homosexuals, abortionists, the entertainment industry and civil libertarians before turning his attention to the perceived threat to the United States from Muslims.

In a chapter titled "Islam: The Deception of Allah," Mr Parsley speaks of Allah as a “demon spirit” and urges "war between Islam and Christian civilisation". There is no difference between violent Islamist extremists and moderate Muslims, he argues.

“I cannot tell you how important it is that we understand the true nature of Islam, that we see it for what it really is,” he writes. “In fact, I will tell you this: I do not believe our country can truly fulfill its divine purpose until we understand our historical conflict with Islam.

“I know that this statement sounds extreme, but I do not shrink from its implications. The fact is that America was founded, in part, with the intention of seeing this false religion destroyed, and I believe September 11, 2001, was a generational call to arms that we can no longer ignore.”

It is not the first time that Mr McCain’s desperation to win over the religious right has landed him in trouble. The Republican had already angered Catholics by cosying up to John Hagee, the leader of an evangelical Texas megachurch who has described the Roman Catholic Church as “the great whore” and a “false cult system”. However the row did not prevent Mr McCain from storming to victory in all four March 4 primaries and laying claim to the party nomination.

Mr McCain had already been forced to dissociate himself from one speaker at the rally, a conservative talk radio host who repeatedly stressed Mr Obama's middle name "Hussein" as he introduced the Republican candidate.

Today, several liberal commentators called on Mr McCain to explain what he meant when he said Mr Parsley was his “spiritual guide”.

Steve Benen wrote on Crooks and Liars: “It’s unsettling, but in this political climate, it’s easier for a right-wing religio-political figure to get away with anti-Muslim animus than anti-Catholic.”

He added: “But if McCain is going to tout Parsley as a “spiritual guide,” it’s certainly worth learning more about where Parsley might “guide” the Republican nominee.”

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