WASHINGTON  As they seek to make good on their campaign promise to roll back President Obama’s health care overhaul, the incoming Republican leaders in the House say they intend to use their new muscle to cut off money for the law, setting up a series of partisan clashes and testing Democratic commitment to the legislation.

Republicans, who will control the House starting in January but will remain in the minority in the Senate, acknowledge that they do not have the votes for their ultimate goal of repealing the health law, the most polarizing of Mr. Obama’s signature initiatives.

But they said they hoped to use the power of the purse to challenge main elements of the law, forcing Democrats  especially those in the Senate who will be up for re-election in 2012  into a series of votes to defend it.

Republican lawmakers said, for example, that they would propose limiting the money and personnel available to the Internal Revenue Service, so the agency could not aggressively enforce provisions that require people to obtain health insurance and employers to help pay for it. Under the law, individuals and employers who flout the requirements will face tax penalties.