A majority of Virginia voters support expanding Medicaid as long as there are federal funds to pay for it, according to a new poll.

The Wason Center at Christopher Newport University found that 56 percent of the state’s registered voters back the expansion of the state-federal health program for the poor, but almost the same number — 54 percent — would oppose it if the federal government did not provide the promised funding.

The poll found that supporters of a federally funded expansion included 55 percent of self-identified Republicans and majorities in every region of the state. But lacking federal funding, only 37 percent of Republicans and 46 percent of Democrats backed expansion.

Under the Affordable Care Act, the federal government is committed to paying 100 percent of the expansion cost for three years and at least 90 percent of the cost thereafter.

Virginia would initially receive about $2 billion a year from Washington if it expanded Medicaid, which would offer coverage to about 400,000 of the state’s uninsured. A recent estimate from the state Health Department projected that expansion would save Virginia about $1 billion over eight years. Among other factors, Medicaid expansion would move many indigent patients to federally funded care.

Republicans in the Virginia General Assembly have argued that both the federal commitment and the projected savings are suspect.

“Obamacare is a train wreck, the program needs serious reform and we cannot trust the empty promises being made by its supporters,” state House Speaker William J. Howell (R-Stafford) and House Majority Leader M. Kirkland Cox (R-Colonial Heights) wrote in a Richmond Times-Dispatch op-ed over the weekend.

That puts the state GOP at an impasse with Gov. Terry McAuliffe (D), who has made Medicaid expansion a major part of his agenda for the state.

According to the poll, half of Virginia voters would rather have the state remain in the federal Medicaid program than seek a waiver to develop a state system; 40 percent would rather the state establish its own guidelines. Most would prefer to stick with employer-based health coverage; only 21 percent would like to be enrolled in a federally run plan.

Also, 53 percent of those responding expressed optimism about the new governor, according to the poll.

The Wason Center, in Newport News, Va., also found widespread support for ethics reform in the state, which has become a top legislative priority amid the scandal surrounding former governor Robert F. McDonnell: 63 percent of respondents endorsed a $250 cap on gifts to elected officials, and 73 percent supported having an advisory commission to review public disclosures. Lawmakers are working on a $250 cap on gifts from lobbyists and others with business before the state.

The poll was conducted Jan. 15-22 and included 1,023 interviews of registered Virginia voters. It has a margin of error of plus or minus 3.1 percentage points.