Gov. Robert F. McDonnell sent a letter Tuesday to President Obama’s health secretary to stress that he and the General Assembly have not agreed to expand Medicaid.

“The recently passed budget of Virginia contains language outlining a series of reforms that must be completed to the satisfaction of a new legislative commission prior to consideration of Medicaid expansion,” McDonnell (R) wrote to Health and Human Services Secretary Kathleen Sebelius. “Some media outlets and elected officials have labeled this as approving Medicaid expansion in Virginia. This is absolutely incorrect.”

The governor wrote the letter at a time when conservative critics are accusing him of giving ground on Medicaid expansion in order to bolster his legacy with a sweeping transportation funding plan.

During the legislative session that concluded Feb. 23, McDonnell signed a written pledge accepting the broad outlines of an agreement on Medicaid expansion. Democrats had refused to vote on the transportation overhaul unless he signed the Medicaid pledge, but his aides insisted there was no link between the two issues.

Democrats meant for the Medicaid language to ease expansion of the health-care program to 400,000 more poor, disabled and elderly Virginians under the federal Affordable Care Act. It does not directly expand Medicaid, as McDonnell’s letter to Sebelius notes. But it authorizes a commission to expand the program if Washington allows the commonwealth to enact specific reforms.

The Medicaid language was a compromise between the House position, which would have required the entire General Assembly to approve expansion, and the Senate’s, which would have let state health officials do so.

Republicans claim to have outsmarted Democrats with the Medicaid language, particularly since the agreement specifies that a simple majority vote of the panel would not be enough to vote for expansion. At least three members from each chamber would have to agree that reform has been completed.

A simple majority of the panel might be more likely to move ahead with expansion because the five members from the more moderate Senate would only need to sway one House member to their side. It is expected to be a tougher sell to convince three members of the more conservative House to go along.

The House members appointed to the commission include delegates who have “deep concerns” about expansion, as McDonnell notes in his letter to Sebelius. (He even sent the secretary a copy of a news release announcing their appointments.)

“The language of the budget actually places a firewall against expansion consideration, unless real, sustainable cost saving reforms are implemented at the state and federal level,” writes the term-limited governor, who leaves office in January.

Despite all the attention Republicans and Democrats alike have devoted to the Medicaid deal, it might not amount to much. The language, included in amendments to the current, two-year budget, expires July 1, 2014 with the advent of the next budget. Many Republicans and Democrats have said that any decision on expansion is likely to fall to the next governor, since the budget language expires six months into his term.

This post has been updated. The original reported incorrectly said that the Medicaid language in the state budget expires July 1, rather than July 1, 2014.