Democratic gubernatorial candidate Terry McAuliffe campaigns at the George Mason University campus in Arlington in this May file photo. (Linda Davidson/The Washington Post)

Democratic gubernatorial candidate Terry McAuliffe toured a nearly complete station on Metrorail’s new Silver Line on Tuesday to highlight his support for Metro’s $6 billion expansion and contrast that with the opposition his challenger in the race, Attorney General Ken Cuccinelli II (R), has expressed toward the project.

“Let’s be crystal clear: We were all for it. Our opponents were all against it,” McAuliffe said. “In fact, Ken Cuccinelli actually said that he would kill it. He wanted to kill it — the only statewide official of either political party who came out against this issue.”

McAuliffe, with attorney general candidate Sen. Mark R. Herring (D) of Loudoun County at his side, touted the Dulles rail project for being “on time and on budget” — an assertion at odds with the project’s managers and critics.

He declined to say whether he would support the kind of labor-friendly provision that nearly upended the second phase of Metrorail’s Silver Line to Dulles International Airport and farther into Loudoun.

“Listen, I’m not going to answer specifics on projects,” he said in response to a question about what is known as a project labor agreement. “You clearly don’t talk about specifics on future projects until you even know what the projects are and what the bidding process will be.”

More Post coverage of the race for Virginia governor.

McAuliffe also declined to say whether he would protect the commonwealth’s status as a right-to-work state or search for ways to make the state more friendly toward organized labor.

“I’m going to work with management. I’m going to work with labor. I’m going to work with everybody to move Virginia forward,” McAuliffe said. “It’s not ‘either-or.’ We are a right-to-work state that has been here for many years, and it’s not going to change. But the focus has got to be not on trying to divide folks. [It] is, how do we work together to grow the Virginia economy to have the most diverse economy to bring in those 21st-century jobs?”

In response, Cuccinelli’s campaign said he would seek more cost-effective ways than the rail project to address Virginia’s perennial traffic woes, such as by giving localities more control over transportation projects. Cuccinelli’s campaign also contrasted his support for protecting Virginia’s right-to-work laws with McAuliffe’s ties to organized labor.

“Yet again, Terry McAuliffe is being the mascot, cheering on the union bosses from whom he’s raised millions of dollars and attempting to take credit for projects in which he had no role,” Cuccinelli spokeswoman Anna Nix said.

The Metropolitan Washington Airports Authority is overseeing the Dulles rail project, one of the largest public transportation projects in the country, and is nearing completion of the first phase. The 11 miles of rail includes five stations and will run between East Falls Church and Wiehle Avenue, on the edge of Reston. The second phase is to run between Reston and Dulles Airport and farther into Loudoun.

The first phase is $150 million over budget, Dulles Corridor Metrorail Project spokeswoman Marcia S. McAllister said Tuesday. But she added that there are built-in project contingencies to allow for unexpected costs. As of April, there was about $62 million left in the contingency fund.

Stephen Barna, senior project manager for the Dulles Corridor Metrorail Project, said crews are working to meet a “substantially complete” deadline of Sept. 9. The system could be operational by late December or early January. The tracks are carrying live electricity, and tests of its automatic control system with trains have been taking place.

McAuliffe, notebook in hand, toured the elevated McLean station as workers installed ceiling panels. More than once, he reminded workers that he and his wife, Dorothy, live on Old Dominion Drive, about a quarter mile away from the station.

McAuliffe said his stance on the Silver Line offers a striking contrast with that of Cuccinelli, who has repeatedly criticized the project. In a two-hour guest spot on WMAL in 2011, Cuccinelli called Phase II of the project an “economic boondoggle” and said he hoped that Loudoun voters elected a Board of Supervisors that would decide to pull out of the project and “to kill it.”

The all-Republican board, after fierce debate, agreed last year to move forward but only after the MWAA had removed the provision that would have given contractors with unionized labor an advantage in securing a piece of the project. A voluntary form of such an agreement has been in place for Phase 1.