A judge has struck down a challenge to block a law that gives New Hampshire auto dealers new protections in their dealings with manufacturers.

Last year, farm and heavy equipment manufacturers like John Deere filed a lawsuit challenging the so-called Auto Dealers Bill of Rights, which they said improperly lumps them in with automakers. The manufacturers said the law is unconstitutional.

Auto dealers had said they had no leverage in agreements with manufacturers that could require them to pay for costly and unnecessary renovations, ultimately driving up costs for consumers.

A Merrimack County Superior Court judge struck down the challenge Thursday.

When she signed the bill last year, Gov. Maggie Hassan said it leveled the playing field between manufacturers and dealers.