BBC News, Washington
A new book by a former US official says President Bush's top political advisers privately ridiculed evangelical leaders, while publicly embracing them.
The Republicans have strong support from evangelical Christians
David Kuo says the aides recognised the religious leaders' political use in securing election victories.
The White House has denied the claims by Mr Kuo, a former official in the Faith-Based Initiatives programme.
The Republican party is concerned the allegations may harm its standing in next month's mid-term elections.
'Alarm bells ringing'
With just weeks to go before what promised to be highly competitive congressional elections, Republicans can ill afford to lose the support of their evangelical Christian base.
So the allegations made in David Kuo's book have set alarm bells ringing in the White House.
The former official alleges senior aides to the president described the evangelical leaders in private as "nuts" and "goofy", while acknowledging their political use in securing election wins.
White House spokesman Tony Snow denied the accusations, saying: "These are people who are friends of many of us in the White House. You don't talk about friends that way."
"When [the president] talks about the Faith-Based Initiative, this is one of these things where he believes years and years down the road... this is going to be one of the signal accomplishments - harnessing the power of faith in dealing with some of the most intractable problems our society faces."
But for the moment it is a short-term goal of keeping a Republican majority in congress that seems most at threat by these revelations.
Republicans are already concerned that the resignation of congressman Mark Foley over lewd e-mails he sent to teenage boys may have dissuaded some religious conservatives from turning out to vote.
This book has the potential to make matters even worse.