PORTSMOUTH, Va. (AP) — The Virginia attorney general's office wants more information from a group that's suing to stop tolls from going up on the tunnels between Norfolk and Portsmouth.

The Virginian-Pilot reports (http://bit.ly/RtOMg4 ) that state lawyers filed a motion Friday saying they need more details to properly defend the Virginia Department of Transportation against the lawsuit filed on July 12.

Among other things, the state wants an explanation of what the Virginia Department Of Transportation is accused of doing that would violate the plaintiffs' constitutional rights. The motion also seeks more information on the plaintiffs to determine their standing to bring the lawsuit. The group includes 31 named individuals, seven companies and an association, Citizens Against Unfair Tolls.

The lawsuit says that VDOT lacked the legal authority to strike the deal with its private partner, Elizabeth River Crossings Opco LLC, and that the General Assembly unlawfully delegated its legislative powers to the state agency.

The plaintiffs are trying to stop a $2.1 billion transportation project that is being paid for tolls, public money, a federal loan and private investment. It will add a second Midtown Tunnel, refurbish the Downtown Tunnel and build a connection between Interstate 264 and the Martin Luther King Jr. Freeway.

Tolls at the tunnels are scheduled to begin in 2014 and will range from $1.59 to $1.84 for cars.

VDOT's agreement with Elizabeth River Crossings lasts for 58 years and allows the tolls to increase by 3.5 percent per year, beginning in 2016. That's when the new Midtown Tunnel is projected to be finished.

Patrick McSweeney, an attorney representing the plaintiffs, said he expects to answer the state's request for more information within a couple of weeks.