RICHMOND –Supporters of a compromise transportation funding package may have to quell dissent in nboth political parties to get the bill through the General Assembly.

One day after Gov. Bob McDonnell urged lawmakers to pass the carefully crafted compromise,  Attorney General Ken Cuccinelli said he can’t support a bill that contains “a massive tax increase.”

Cuccinelli’s criticism underscores an emerging rift in the Republican Party over a proposed transportation funding package that House and Senate negotiators agreed to on Wednesday. The plan would produce about $3.5 billion in new, statewide transportation funds over the next five years, according to legislative projections. The House and Senate likely will vote on the compromise Friday.

Democrats also raised the prospect of conditioning their support for the transportation bill on approval for the expansion of Medicaid, something McDonnell has resisted. McDonnell sent a letter to legislative budget negotiators Wednesday reiterating his opposition to expanding Medicaid without first getting a guarantee of major cost reductions.

The transportation plan would scrap the state’s 17.5 cents per gallon tax on gasoline and apply a 3.5 percent tax on the wholesale price of fuel. It also would increase taxes on retail and automobile sales, impose a 6 percent tax on the wholesale price of diesel fuel, and dedicate a greater portion of the sales tax to help fund road, rail and transit needs.

McDonnell has made transportation funding a top priority in his final legislative session.  House Speaker Bill Howell, R-Stafford County, has been a key legislative ally and has endorsed the compromise. Eight of the 10 House and Senate negotiators who brokered the deal are Republicans.

Republican Lt. Gov. Bill Bolling, who is weighing an independent bid for governor, also has backed the compromise.

McDonnell said the passage of the bill “will strengthen Virginia’s economy, help create thousands of good paying jobs, and improve the lives of every Virginian in every city and county.”

But Cuccinelli,  a tea party hero who hopes to succeed McDonnell in the governor’s office, took a different view of the compromise.

“If reports are correct, this new bill contemplates a massive tax increase,” Cuccinelli said in a statement released by his office . “In these tough economic times, I do not believe Virginia’s middle class families can afford massive tax increases, and I cannot support legislation that would ask the taxpayers to shoulder an even heavier burden than they are already carrying, especially when the government proposes to do so little belt tightening in other areas of the budget.”

Cuccinelli noted the he has not seen the conference report on the transportation bill and said lawmakers “should have the opportunity to thoroughly review this new legislation in its entirety once it becomes available, evaluate the fiscal impact it will have on the people of Virginia, and determine if this proposed legislation will actually resolve our serious transportation problems before it is brought to the floor for a vote.”

Some conservative legislators and anti-tax groups were quick to criticize the plan after House and Senate negotiators released details of the compromise on Wednesday.

“When you combine these tax increases with the looming sequestration coming out of Washington, it’s a devastating one-two punch on Virginia families and small businesses,” said Del. Ben Cline, R-Rockbridge County, the House chairman of the legislature’s Conservative Caucus.

Grover Norquist, the president of Americans for Tax Reform, said the transportation bill was “hijacked by a number of Republicans who join Democrats in believing that all transportation costs must be paid for by higher taxes.”

Democratic votes will be needed to pass the plan, perhaps even in the Republican-dominated House of Delegates. When the House passed the original version of McDonnell’s transportation bill earlier this month, four Democrats delivered key votes to get the bill throughchamber with a slim majority. One of them, Roanoke Del. Onzlee Ware, was named to the conference committee that hammered out the compromise.

Some Democrats have discussed withholding support for the transportation bill until McDonnell and House Republicans agree to expand the Medicaid program under the federal health care law. McDonnell has said he will not agree to the expansion — which the federal government will fully fund for three years — without federal approval of cost-cutting reforms. The issue is tied up in budget negotiations between the House and Senate.

“There’s a lot of discussion about, ‘Look, transportation is important, but getting Medicaid expansion is just as important,’” said Sen. John Edwards, D-Roanoke.

Ware said it would be a mistake to link Medicaid expansion to the transportation bill. He said the strategy would “put the transportation bill in danger.”

Terry McAuliffe, the presumptive Democratic nominee for governor, said Wednesday that he supports the compromise even though he doesn’t like some elements of the plan.

“However, Virginians are demanding that we compromise to find a mainstream solution and that compromise will necessarily be imperfect for both sides,” McAuliffe said in a statement .

“Virginia simply cannot afford to miss this opportunity to make substantial progress on transportation,” McAuliffe said. “If we want the commonwealth to be the best place for business and jobs of the future, we need to have a transportation system that is modern and efficient.”

McAuliffe campaign spokesman Josh Schwerin said Cuccinelli is trying to derail the compromise.

“Cuccinelli’s work to undermine this mainstream proposal reflects his unique unwillingness to compromise under any circumstances,” Schwerin said in an email. “Once again, Ken Cuccinelli has demonstrated that his ideological agenda is outside even the Republican mainstream.”

– Michael Sluss