(AP)—House Republicans are coming to the aid of high-risk patients trying to get insurance under the new health care law. But they do so by diverting money from a prevention program that is key to the law, ensuring stiff opposition from Democrats and a veto threat from the White House.

The GOP bill would provide up to $3.6 billion to ensure that people with pre-existing conditions continue to have access to private coverage until Jan. 1, when the law will fully take effect. In February the administration said it would stop taking applications for the Pre-Existing Condition Insurance Plan because it was running out of money.

Democrats say the measure would take money from a that is critical to the law's success.

A vote is expected Wednesday afternoon.