Republicans are challenging Democratic Party gubernatorial candidate Terry McAuliffe’s claim to helping push a major transportation-funding package through the Virginia General Assembly this year.

The GOP pounced soon after McAuliffe’s camp put out a TV ad that attempts to link him to transportation legislation backed by Gov. Robert F. McDonnell (R). McAuliffe’s statewide ad, entitled “Too Important,” is the second of his campaign and depicts McAuliffe as rising above partisan politics to support the measure.

“A landmark transportation bill is up for consideration in the Virginia legislature,” the ad says. “Even though it’s backed by Republican Gov. Bob McDonnell, tea party Republicans refuse to support the plan. But Terry McAuliffe thinks this is too important a time for partisan politics. McAuliffe reaches out to Democrats and urges them to support the bill, and the bill passes.”

McAuliffe’s campaign Web site goes slightly further, saying he worked with members of both parties to pass the bill.

Republicans, focusing on the closing lines of the 30-second TV spot, said the ad falsely implies that McAuliffe’s lobbying played a decisive cause of the bill’s passage. Sen. Walter A. Stosch (R-Henrico), who chairs the Senate Finance Committee and chose the 10 conferees who reached compromise on the transportation bill, said that even by the standards of a political ad, McAuliffe’s claim “stood out for its absurdity.”

“The new ad implies that somehow McAuliffe was instrumental in bringing the transportation package across the finish line,” Stosch said Tuesday in a written statement. “His attempt at claiming credit where none is due is an example of self-puffery that frankly deserves a prompt correction.” America Rising PAC took another whack at McAuliffe on Wednesday, posting an item on Tumblr that dubbed him “Terry the Exaggerator.”

But Democrats say the ad, strictly parsed, is entirely true: McAuliffe made some calls, and the bill passed.

“That’s absolutely accurate,” Sen. Janet D. Howell (D-Fairfax) said Wednesday. “In a way, I’m not disagreeing with Stosch when he was saying McAuliffe didn’t help craft the bill. What McAuliffe was doing was helping to get it passed ... And that’s a stark contrast to Cuccinelli.”

That would be Attorney General Ken Cuccinelli II, the GOP’s gubernatorial candidate. Cuccinelli, who has promoted himself as an unwavering conservative, spoke out against the transportation measure as a “massive tax increase.” As attorney general, he twice raised legal objections that threatened to scuttle the transportation deal. Yet he also offered guidance on ways to make legislative fixes that would pass legal muster.

McAuliffe, by contrast, called McDonnell to congratulate him on the bill’s passage. McAuliffe, the former Democratic National Committee chairman and fundraiser who never held elective office, has built his campaign around his reputation as a dealmaker and entrepreneur.

Polls show the two in a tight race that has been notable for the early mudslinging, even as both campaigns try to define their candidates as focused on job creation and other economic issues.

McAuliffe campaign spokesman Josh Schwerin, in an email Wednesday, said that McAuliffe and his staff talked with McDonnell and Lt. Gov. Bill Bolling (R) , about how McAuliffe could help pass the bill.

Bolling — who pulled the plug on his gubernatorial hopes after Cuccinelli entered the race — said on NewsTalk with Bruce DePuyt that McAuliffe was an “ally” who lined up support for the bill. Democratic lawmakers said McAuliffe also spoke to the House of Delegate’s Democratic Caucus and dialed up Democrats who were wavering, as noted in news articles at the time.

“It might not have passed that day if he had not made those calls,” Del. Scott A. Surovell (D-Fairfax) said Wednesday.

But this was news to several Republican lawmakers who worked well into the night with Democrats to cut a deal that would pass the GOP-led House and the evenly divided Senate.

“[McAuliffe] was nowhere to be found during the workings of the transportation bill,” said Sen. Frank W. Wagner, a Virginia Beach Republican who served on the transportation conference committee. “I can appreciate people taking credit for things they weren’t involved in, but having been intimately involved in the process, that never came up as a factor.”

Del. David B. Albo (R-Fairfax), another conferee, said he never heard from McAuliffe. Nor did Albo know of other Republicans or Democrats whom McAuliffe contacted about passing the bill.

“The only real player on the Democratic side of the House of Delegates was Vivian Watts – and I can’t understate what she did, because she did a lot,” Albo said.

Several key Democrats who put the compromise together, including Watts, said McAuliffe showed a keen interest in the bill and its progress. But they were less certain about McAuliffe’s efforts as a party whip.

“Terry called me twice to ask how things were going,” Del. Onzlee Ware (D-Roanoke), a member of transportation conference committee, said Wednesday, adding that there was not a lot he could tell McAuliffe because of the sensitive nature of the talks. “I can’t speak to what he told other caucus members.”

Among those Democrats whose support was doubtful was Sen. J. Chapman “Chap” Petersen (Fairfax). But Petersen, who ultimately voted against the transportation bill, said McAuliffe never called to try persuading him to rethink his views – not that that might have mattered.

“Quite frankly, I trust my own instincts on these things,” Petersen said Wednesday.

Watts (D-Fairfax) said she could not speak to whether McAuliffe had lobbied others or actually corraled any votes. But Watts, who served as former governor transportation secretary under former governor Gerald L. Baliles, said that McAuliffe met with her before the annual legislative session for at least hour because he wanted to understand the intricacies of transportation funding.

“This is a mark of a good governor when you respect and pull together people who have detailed knowledge,” Watts said. “The depths of the way in which he picked my brain were terribly important.”