Ken Cuccinelli gives a speech at the Conservative Political Action Conference at the Gaylord Hotel National Harbor in Oxon Hill, Maryland, on March 14, 2013. (Marvin Joseph/The Washington Post)

A liberal super PAC is taking aim at Attorney General Ken Cuccinelli II for his opposition to the state’s transportation funding overhaul, which comes back to the General Assembly this week.

In a Web video released Monday, American Bridge 21st Century calls the presumptive Republican nominee for governor “a roadblock for transportation.”

“I’ve never been for this bill,” Cuccinelli says in an audio snippet taken from an interview he gave on the Jimmy Barrett Radio Show on WRVA last week.

The video also accuses Cuccinelli of taking contradictory positions on the plan. The radio host is heard noting that Cuccinelli “wasn’t a big fan” of the legislation, but “it didn’t stop you from claiming some of the credit for getting it through the legislative process.”

“Voters see through Ken Cuccinelli’s cynical efforts to claim a share of the credit for the bipartisan transportation deal he opposed every step of the way,” said Chris Harris, communications director for American Bridge. “Virginians need a leader on transportation, not a roadblock.”

Cuccinelli has opposed the $1.4 billion-a-year plan as a “massive tax increase.” And in a legal opinion, he said the way the original bill would have raised some regional tax revenue in Northern Virginia and Hampton Roads was unconstitutional.

But in the same opinion, Cuccinelli also provided a roadmap for resolving those constitutional issues by basing special taxes on not geography, which he says is not allowed, but on other criteria, such as population.

After Gov. Robert F. McDonnell (R) proposed amending the bill as Cuccinelli had suggested, the attorney general’s campaign issued a news release touting his role in “making sure the legislation was able to move forward without the threat of any legal challenges.”

Cuccinelli’s campaign said he continues to oppose the plan as a matter of policy, but he put his own feelings aside as he assessed the bill’s constitutionality and provided solutions to problems he’d solved.

“Ken Cuccinelli has already made known his concern about the funding mechanisms in the transportation bill,” campaign spokeswoman Anna Nix said. “However, as attorney general, his job is to advise the governor and legislators on ways to ensure legislation is constitutional — and he does so regardless of his personal beliefs on legislation. Cuccinelli looks forward to sharing his ideas in the upcoming weeks on how to help ease congestion while creating jobs in Virginia.”

Cuccinelli faces Democrat Terry McAuliffe, who supports the transportation bill, in the race to succeed term-limited McDonnell.

The bill comes before the General Assembly Wednesday, when legislators reconvene to consider McDonnell’s proposed amendments to that and other legislation.