PORTLAND — A panel of federal judges expects the Legislature to redraw the boundaries between Maine’s two congressional districts by Sept. 30 and that the state’s supreme court would finish the work by Nov. 15 if lawmakers are unable to complete the task in time.

If the Legislature and the Maine Supreme Judicial Court do not adhere to the deadlines, the federal judges will reapportion Maine’s congressional districts before Jan. 1, 2012  – the date when nominating petitions become available to congressional candidates. The panel set the deadlines and outlined the procedure in an order issued today.

If state officials don’t appear to be working fast enough to meet their deadline, the judges may impose a new schedule to make sure the judges themselves are able to complete redistricting by the end of the year.

The judges ruled earlier this month that the current apportionment is unconstitutional because of population disparities revealed in the 2010 census and that the congressional districts must be redrawn in time for the 2012 election. Maine would have normally made its next readjustment in 2013.

The lawsuit against state officials was filed by two Cape Elizabeth residents – William DeSena and Sandra Dunham – who argued that their votes would be diluted if the districts weren’t redrawn to reflect the southward population shift. The census showed that the population of the southern, coastal 1st Congressional District had grown to 668,515 while the 2nd District’s population was 659,848.

The plaintiffs and the defendants – Gov. Paul LePage, Senate President Kevin Raye, House Speaker Robert Nutting and Secretary of State Charles Summers – agreed that it would be unconstitutional to go into the 2012 without readjusting the districts. The Maine Democratic Party, an intervenor in the case, argued the integrity of a methodical, bipartisan process was at risk.

The judges – Bruce Selya of the 1st Circuit Court of Appeals, D. Brock Hornby and George Singal – ruled that the state must strive toward  “precise mathematical equality” and make the districts “nearly as equal as is practicable under all the circumstances.”

The order issued today did not spell out the details of how the Legislature and state supreme court should do their work.

Maine’s practice has been to create a 15-member bipartisan commission to develop a plan. The Legislature would need a two-thirds majority to enact that plan or one of its own. If the Legislature isn’t able to act before its deadline, the state supreme court would redraw the boundaries after taking public input.