Comptroller Peter Franchot came out swinging Tuesday against Gov.Martin O'Malley's proposal to apply the state's 6 percent sales tax to gasoline, denouncing it as a "shot to the gut" of middle-class consumers and small businesses.

As expected, the comptroller used a roundtable he staged in Annapolis to showcase the petroleum industry's objections to any gas tax increase in general and to the sales tax  on fuel in particular.

The event put even more distance than already existed between Franchot and O'Malley, a fellow Democrat.

Even before O'Malley unveiled his proposed phase-in of a sales tax on gas, Franchot was on record opposing any additional tax on fuel -- arguing that the economy remains too weak.

"I urge everybody to take a time out and consider very carefully what the consequences would be," he said.

Franchot said he's been all over the state and has found little support for a gas tax increase except from a few "elite business executives" in Baltimore and Senate  PresidentThomas V. Mike Miller-- one of his a perennial targets.

"Whether it's an excise tax or a sales tax, I believe it's a very dumb idea," he said.

The comptroller declined to say what alternatives he would suggest for transportation funding.

"I'm going to leave that to the governor and the legislature. That's their policy job to propose," he said.

If a transportation revenue measure is not approved this year, the second year of a gubernatorial term, the chances of its winning passage are unlikely to improve as the next election nears. While transportation advocates say the backlog of unmet needs is growing, such measures are never popular.

Franchot did say he'd be willing to accept delays in some major transit projects now in the works -- including the Purple Line and Corridor Cities Transitway in his home county of Montgomery -- rather than increase transportation revenue now. As Franchot moves closer to a 2014 gubernatorial run, it will interesting to see how that plays with voters who made up his base when he defeated William Donald Schaefer for comptroller in 2006.