Maryland Gov. Martin O’Malley (D) on Wednesday lashed out at a fellow state Democrat for criticizing the governor’s proposal to raise the state’s gas tax, calling Comptroller Peter Franchot the party’s own “version of Mitt Romney.”

The attack drew a sharp response from Franchot (D), who quipped that he was “sorry” if he was getting in the way of O’Malley’s “presidential efforts.”

Maryland Gov. Martin O'Malley (AP Photo/Patrick Semansky)

But Wednesday’s testy exchange also amounted to a new high-water mark in growing tension between O’Malley and other prominent state Democrats who have begun to position themselves for a possible run at the governorship to succeed O’Malley in 2014.

Comptroller Peter V.R. Franchot (D) during a visit to Piccowaxen Middle School on Tuesday. (Gretchen Phillips)

Asked by a reporter about Franchot’s criticism, O’Malley stressed that the comptroller had flip-flopped on raising the gas tax, noting he supported it previously.

“He’s kind of our version of Mitt Romney, I mean, he’s very happy taking opposite sides of every issue and always has throughout his career,” O’Malley said, adding that Franchot had changed his stance on slots casinos, too. “He’s decried legalized gambling, and also supported bills for legalized gambling. He’s supported bills to increase the gas tax, and now he decries the gas tax.”

Franchot supported a gas tax increase before the downturn, but over the last year has lobbied for gas-tax holidays.

Told about the governor’s remarks, Franchot returned fire:

“I’m sorry if I’m getting in the way of his presidential efforts, but I’m doing my job,” Franchot said, keying in on a criticism that O’Malley has taken on a larger role as a surrogate for President Obama — perhaps at the expense of his work in Annapolis.

“It’s hard enough to focus on the bricks and mortar and dollars of the state budget, and to try to keep our fiscal house in order without having a national campaign brought into Maryland,” Franchot said.

O’Malley has appeared on national television twice this week, and in the last month traveled to South Carolina to campaign against Mitt Romney and to New York to meet with Democratic governors. Later in February, he also has several events scheduled in Washington in connection with his role as the head of the Democratic Governors Association.

However, a month into the General Assembly’s 90-day session, O’Malley said he was pleased the legislature had already held one hearing on whether to legalize same-sex marriage, and noted another is scheduled for Friday.

He also voiced confidence that lawmakers would come around to his plan to close a $1 billion budget shortfall in part by increasing income taxes on those making over $100,000, and sharing teacher pension costs to counties.

“I think they’ll conclude the option we laid before them was the most socially responsible way to go,” O’Malley said, adding he didn’t expect answers on many of his bills until late in the session.

“The most intense time of the session is at the end, that’s when all of the decisions have to be made,” he said.