As Rhode Island Sen. Lincoln Chafee (R) posted another disappointing fundraising number for the most recent quarter, the National Republican Senatorial Committee continues its television assault on his primary challenger.

The NRSC, which has been running an ad called “Slick” — accusing Cranston Mayor Stephen Laffey (R) of hypocrisy on the issue of high gasoline prices — since Oct. 3, will begin airing a second spot today.

No further details were available as of press time Friday, but the NRSC confirmed that it had drafted and was running another ad.

Although Chafee is considered one of the two most vulnerable Republican Senate incumbents of the 2006 cycle, he has not been raising money like a man who may lose his seat.

For the three-month period that ended Sept. 30, Chafee raised just $287,000 — less than Laffey or either of his main Democratic rivals.

“We’re not concerned — over the course of the cycle Sen. Chafee has raised more than all three of his opponents; he has raised more than $1.7 million,” said Chafee campaign spokesman Ian Lang.

That includes all the money Chafee has raised since his 2000 election.

One reason for the less-than-stellar performance is that Chafee postponed a major fundraiser featuring Commerce Secretary Carlos Gutierrez in the wake of Hurricane Katrina, Lang said.

The event, originally slated for Sept. 9, will be held Oct. 28 in Providence.

“It’s going to be a significant event,” Lang said.

Chafee raised $436,000 from April to June 30, which was far more than the $139,000 he raised in the first quarter of the year.

He reported $1.28 million in the bank as of Sept. 30.

By contrast, Laffey, who only entered the race Sept. 8, raised $743,000 — about half of which came from his own pocket.

On the Democratic front, former state Attorney General Sheldon Whitehouse collected more than $600,000, and Rhode Island Secretary of State Matt Brown took in more than $400,000 in the third quarter.

Laffey and Brown both banked around $600,000, while Whitehouse had socked away close to $1.4 million.

Lang said Chafee is satisfied with his overall fundraising performance.

“We’re OK with where we are,” Lang said.

Chafee has considerable personal wealth from which he can draw if he chooses. Although Lang would not say if Chafee plans to dip into his family trusts, he did not rule it out either.

“The Senator will do whatever it takes to win this election,” Lang said. “We’re going to run an aggressive campaign and get our case out to the people.”

The NRSC buys demonstrate how concerned Republican leaders in Washington, D.C., are about Laffey’s primary challenge, and signal their desire to shut Laffey down well ahead of next September’s primaries.

National Republican leaders, including NRSC Chairwoman Elizabeth Dole (N.C.) and top White House political adviser Karl Rove, had tried to dissuade Laffey from running against Chafee.

State GOP leaders, including the Republican governor, reportedly offered Laffey other positions to keep him out of the primary.

With all negotiations having failed and Laffey stumping around the state sounding populist themes, the NRSC began attacking Laffey from the get-go.

As a pre-emptive strike aimed at discouraging the conservative Club for Growth from weighing in on Laffey’s behalf, the NRSC distributed a research memo documenting how Laffey raised taxes since becoming mayor in 2003.

Political observers speculate that the latest NRSC ad will focus on the tax issue as well.

Laffey also has been on the air already.

On Sept. 13 he began running “Mess,” which focused on high gasoline prices and derided both Republicans and Democrats for contributing to the “mess” in Washington.