A controversial new personnel system affecting nearly 5,000 Portsmouth Naval Shipyard workers and roughly 700,000 civilian defense workers elsewhere is on hold at least until March 1.

A federal judge in Washington, D.C., got both sides to agree to the delay Tuesday during a hearing on a lawsuit filed by unions to block the system.

“It’s an extremely important case and it is extremely complex,” U.S. District Judge Emmet Sullivan said during a three-hour hearing.

The unions claim the National Security Personnel System would violate federal law by undercutting the workers’ right to collective bargaining. The Defense Department says it needs the rules, which would make it easier to hire, fire and discipline employees, to fight the war on terror effectively.

The Metal Trades Council is one several affected unions at the shipyard, which is in Kittery. Council President Paul O’Connor called the delay good news.