Members of the House voted 265-159 Tuesday to approve H.R. 976, a compromise version of the State Children's Health Insurance Program Reauthorization Act bill.
President Bush has threatened to veto the bill, arguing that it is too expensive and could crowd out private children's insurance coverage.
The Senate is expected to approve H.R. 976 later this week by a wide margin, but supporters do not appear to have enough votes in the House to come up with the two-thirds majority needed to overcome a veto.