By Jonathan Allen, CQ Staff

The move by an arm of the National Republican Congressional Committee (NRCC) to scale back campaign support for embattled Reps. Michele Bachmann and Marilyn Musgrave drew a sharp rebuke from the leader of a prominent organization of social conservatives, who is vowing to tell his supporters not to donate to the GOP’s House campaign unit unless the decision is reversed.

“It appears that the NRCC is abandoning social conservative candidates and the issues for which they stand, particularly if they are championed by some of the most promising female legislators in the Congress. This is no time to cut and run from a fight,” Family Research Council (FRC) President Tony Perkins wrote in a letter to NRCC Chairman Tom Cole , who represents an Oklahoma district in the House. The letter was released to reporters late Thursday.

Referring to his organization’s political action committee, Perkins warned, “I will urge supporters of the FRC Action to stop giving to the NRCC until it starts supporting and fighting for conservative candidates in close races.”

Musgrave, who survived a very close 2006 contest in Colorado’s 4th District, appears in even more political danger in her contest this year with Democratic businesswoman Betsy Markey, a former aide to Colorado Democratic Sen. Ken Salazar . Bachmann appeared a much stronger favorite in Minnesota’s strongly conservative-leaning 6th District, but her race against Democratic former state official Elwyn Tinklenberg has tightened since last week, when she made controversial remarks on national television questioning whether Democratic presidential candidate Barack Obama has “anti-American views.”

NRCC officials, though, defended their committee, saying they have no control over how advertising dollars are spent by their independent expenditure (IE) unit, with which they cannot coordinate under federal campaign law.

In a memo to reporters, NRCC spokeswoman Karen Hanretty noted that some candidates, including Bachmann, are in better position than others to defend their seats without help from the national party.

“There are more paths to victory for Republican candidates than we have money to fund. Some candidates, like Congresswoman Bachmann, are sitting on more than $1 million cash on hand in districts that President Bush won in 2004 by double digits,” Hanretty wrote.

The fight between the FRC and the NRCC comes at a time when Republicans are relying heavily on turnout by conservative voters to act as a buffer against a strong Democratic push for the Nov. 4 elections, both in the presidential contest between Obama and Republican John McCain and in congressional races that are expected to produce Democratic gains for the second consecutive election cycle.

The GOP can hardly afford to alienate voters who are motivated by socially conservative causes. And expenditure records indicate that the NRCC’s independent expenditure outfit has spent heavily on social conservative candidates — including Musgrave, who has been bolstered by $772,659 in NRCC IEs through Oct. 21 according to figures compiled by the Campaign Finance Institute. That ranks her third among all Republicans, behind fellow social conservatives Tim Walberg of Michigan’s 7th District ($931,670) and Steve Chabot of Ohio’s 1st District ($777,854), both of whom also are facing highly competitive Democratic challenges.

NRCC officials disputed the thrust of Perkins’ charge that the party organization was abandoning socially conservative candidates. “Mr. Perkins’ letter is puzzling, considering that the NRCC’s IE unit has spent money on candidates who are pro-life conservatives by a margin of 2-to-1,” said an NRCC source who declined to be identified by name.

But an NRCC aide confirmed that planned television advertising purchases on behalf of Bachmann and Musgrave in the campaign’s final days, as well for endangered Reps. Tom Feeney in Florida’s 24th District and Joe Knollenberg in Michigan’s 9th District, had been canceled.

Bachmann and Musgrave are viewed as leading allies of social conservatives in Congress because they have been vocal advocates of banning same-sex marriage.

Bachmann turned a relatively sleepy re-election bid in her Minnesota district — which runs northwest from St. Paul suburbs to St. Cloud — into a barn-burner with her comments about Obama and a suggestion that the media should launch an investigation into whether members of Congress are “pro-America” or “anti-America.”