The state of Maryland says gun advocates waited too long to challenge tougher firearm regulations set to take effect Tuesday.

Attorney General Doug Gansler asked a federal judge in Baltimore on Monday to deny their request for an order blocking enforcement of the law.

A collection of gun shops, firearm associations and private citizens filed two lawsuits late last week challenging different aspects of the law on constitutional grounds. A court hearing on the first case is set for Tuesday.

Gansler says the plaintiffs sat on their claimed rights for six months after Gov. Martin O'Malley signed the measure. He says the motion should be denied for that reason.

Gansler also says the plaintiffs haven't shown that the challenge is likely to succeed, or that implementation will cause irreparable harm.

