WASHINGTON — Obama administration attorneys are urging a federal judge to throw out an election-year lawsuit by House Republicans over the president’s health care law.

Attorneys for the House counter that their unusual suit deals with critically important issues related to the separation of powers and should be allowed to continue.

The two sides meet in court for the first time today in a hearing before U.S. District Judge Rosemary Collyer, a 2003 appointee of George W. Bush. It comes as the Obama administration and lawmakers of both parties anxiously await a Supreme Court ruling on a different lawsuit that challenges other portions of the health law and threatens insurance subsidies for millions of Americans.

The House suit, authorized by frustrated House Republicans last summer over strenuous objections from Democrats, may not make it that far. Previous attempts by members of Congress to sue past administrations have been tossed out, although the House health lawsuit is the first by the full House against a sitting president.

In the lawsuit the House contends that the Obama administration usurped the legislative role reserved for Congress by acting administratively to approve certain payments to insurers and delay deadlines in the law without Congress’ say-so.

“This case addresses fundamental issues regarding the limits of executive power under our constitutional form of government,” attorneys for the House said in court filings ahead of Thursday’s hearing. “One fundamental tenet of our divided-power system of government is that all legislative power is vested in Congress, and Congress alone.”

Government attorneys argued that the House could show no direct injury and instead based its lawsuit on general objections to how the Obama administration is implementing the law, which they said doesn’t justify its suit.

“This novel tactic is unprecedented, and for good reason: the House has no standing to bring this suit,” Justice Department attorneys argued. “The House here asserts only that the executive branch is implementing statutory provisions, which were enacted by a previous Congress, in a manner different from what the current House would prefer.”