It's impossible to repeal only parts of the new healthcare law without undermining it entirely, House Speaker Nancy Pelosi (D-Calif.) said Monday.

Pelosi challenged Republicans who have said they wish to repeal, in part or in whole, the new healthcare law passed by Democrats and signed into law last week by President Barack Obama.

The speaker rejected claims by some GOP lawmakers that certain provisions of the new healthcare reform law are acceptable, only to repeal many of the other reforms in the legislation.

"Some of them will say, 'I'm okay with that, but don't want the rest of it,'" Pelosi said during remarks at a senior center in San Francisco. "Well you can't have some without the rest of it, because you need it to hold the insurance companies responsible."

Republicans have made repealing broad swaths of the new healthcare law a central aspect of their 2010 campaign strategy. Leaders in the GOP, though, have stressed theirs is a campaign of "repeal and replace," which would conceivably put into place reforms which Republicans have pushed over the past year, some of which overlap with Democrats' reforms.

The rhetoric previews what is expected to be a pitched battle over repealing healthcare in this fall's congressional elections, a campaign theme which Democrats have said they welcomed.

"They want to reverse and repeal a prohibition on denying care on the basis of a preexisting conditions?" Pelosi asked, pointing to a litany of other reforms that would be wiped out by a full repeal of the bill.