President Barack Obama Monday will huddle at the White House with Sen. Bob Casey (D-Pa.), an anti-abortion rights Democrat who has been trying to negotiate a compromise on the issue as part of a health care overhaul.

White House officials were not available to comment on the substance of the meeting.

Abortion is a key sticking point in the health care debate. Sen. Ben Nelson (D-Neb.), a key vote for supporters of the $848 billion bill, has said he will oppose the bill if its abortion language is not changed. Nelson reiterated that stance over the weekend.