Washington (CNN) A panel of three federal judges in North Carolina ruled Monday the state's congressional map is an unconstitutional partisan gerrymander that favors Republicans, and said it may require districts to be redrawn before the November elections.

Republicans hold 10 of the state's 13 seats in the House of Representatives, and a redrawn map could put more seats in play for Democrats -- potentially affecting control of the House.

The judges acknowledged primary elections have already occurred, but said they were reluctant to let voting take place in districts that courts twice found had been unconstitutionally drawn.

The same decision was reached by the court in January, but the Supreme Court declined in June to hear the case and it was sent back for reconsideration. The Supreme Court has never ruled a partisan gerrymander to be unconstitutional, and it passed up three separate opportunities to do so in the last term.

The decision Monday could result in an election-year appeal to the Supreme Court. The court is currently evenly split on ideological lines and lacks a ninth justice to tip the scale. The court also traditionally does not approve of judicial actions so close to an election that could affect the outcome.