A pair of Democratic senators from Baltimore County are among those challenging the constitutionality of the legislative redistricting plan that became law in Maryland earlier this year.

Sens. James Brochin and Delores G. Kelley allege in a filing with the Court of Appeals that the map submitted by Gov. Martin O’Malley (D) is problematic because of a redrawn district that crosses the line between the city and county of Baltimore.

That district, the petition alleges, has “shoved” several Baltimore County districts northward, making them much less compact than they have been for the past decade. The Maryland constitution requires that legislative districts be “compact in form” and consist of “adjoining territory.”

The filing also argues that the new plan skews the power of Baltimore city at the expense of the county.

The new map became law in February after the legislature declined to act on the plan submitted by O’Malley (D).

Dan Friedman, a lawyer from the Attorney General’s Office who represents the legislature, declined to comment on the specifics of the filing by Brochin and Kelley.

But, Friedman said, “it is my view that the plan is constitutional and legally sufficient, and we look forward to proving that to the court.”

The constituencies of both Brochin and Kelley change considerably under the new map. Brochin’s district is set to become less Democratic and is expected to pose the greater challenge to his re-election.

Several other parties have challenged provisions in the new legislative map as well.