House Republicans on Tuesday called for a special legislative session on Medicaid expansion, a surprise move meant to extricate the issue from the state budget, avert a potential government shutdown — and put Democrats on the defensive.

With just days left in the regular session, the evenly split Senate and GOP-dominated House are deadlocked on whether to expand Medicaid under the federal health-care law known as Obamacare.

Republicans have complained all session that inserting Medicaid into the budget was a way for Democrats to hold state spending hostage to expansion. Plucking the issue out of the two-year, $96 billion budget plan and taking it up in a special session would force the issue to rise or fall on its own merits.

The call for a Medicaid session was intended to “free the budget hostage,” as one Republican delegate put it, and allow a GOP tarred with the “party of ‘no’” image to appear proactive and ready to engage. The offer was not expected to generate any Democratic takers, since severing Medicaid from the budget would undermine the only leverage the Senate appears to have with the House.

House Republicans have been immune to Gov. Terry McAuliffe’s charm offensive and arm-twisting, resistant to lobbying from business and hospital groups, and dismissive of the Senate’s “private option” take on expansion. McAuliffe (D) has sought to increase pressure on the GOP in recent days with appearances at hospitals around the state. Republican House leaders responded by mocking the governor for leaving town instead of staying in Richmond to work on the budget.

“Virginia’s budget should not be held hostage to one particular issue,” said House Speaker William J. Howell (R-Stafford). “Governor McAuliffe and the Senate should let the General Assembly pass a clean budget with no strings attached. Once that happens, he should call a special session to debate the issue of Obamacare’s Medicaid expansion.”

Democrats called the suggestion a ploy, not a sincere invitation to hammer out a bipartisan expansion plan. House Minority Leader David J. Toscano (D-Charlottesville) said he would take Republicans up on their offer only if they “can assure us that the special session is to work out the details of Medicaid expansion.”

“ ‘Just say no’ is not a policy,” Toscano said.

Asked what the governor thought of calls for a special session, McAuliffe’s office did not respond directly.

“The Governor remains hopeful that House Republicans will come to the table to pass a budget on time that includes the common-sense measure proposed by their Republican Senate colleagues to accept federal funding to close the coverage gap,” Rachel Thomas, a McAuliffe spokeswoman, said in an e-mail. “Every day that Republicans say ‘no’ wastes another $5 million in taxpayer money that could go to covering up to 400,000 Virginians, creating 30,000 jobs and saving our budget $1 billion by 2022.”

Republicans reached back to McAuliffe’s campaign rhetoric to make their case for severing Medicaid from budget negotiations, which Republicans have said are remarkably close to completion in every other area. At a morning news conference and again on the House floor, GOP leaders displayed a poster-size replica of a letter candidate McAuliffe wrote to the state’s congressional delegation on the eve of a federal government shutdown last fall.

“I urge all members of Virginia’s congressional delegation to stop using the threat of a government shutdown as a bargaining chip in other negotiations, including over the health care law,” McAuliffe wrote at the time.

Three Senate Republicans support expansion, but GOP leaders from that chamber chimed in, calling on McAuliffe to “abandon obstructionist tactics.”

“Now-Governor McAuliffe is employing the same tactic he once denounced, endangering the budget process and steering the Commonwealth toward a shutdown,” said Senate Minority Leader Thomas K. Norment Jr. (R-James City) in a prepared statement.

Joining the GOP leaders in their call for a special session was the lone Republican House member who supports Medicaid expansion, Del. Thomas Davis Rust (Fairfax), who warned that delaying the budget would hurt localities.

The Virginia Chamber of Commerce, which has been a vocal supporter of expansion, issued a letter Tuesday that said budget delays could threaten the state’s reputation as a well-managed state and jeopardize its stellar AAA bond rating.

Under the Affordable Care Act, states have the option to expand Medicaid to people making up to 138 percent of the federal poverty line, which is an annual income of $23,850 for a family of four. House Republicans say Washington is too broke to make good on its promise to foot most of the bill, which in Virginia would amount to $2 billion a year.

The Senate came up with a plan meant to be more palatable to House conservatives. Called Marketplace Virginia, it would use the Medicaid money to buy private insurance for enrollees, who would be required to contribute significant co-pays. They would also have to work or show they are looking for a job. Advocates say Virginia could opt out of the deal if federal funding dries up.

The House did not include expansion in its budget and rejected the Senate plan in a symbolic floor vote last week. Opponents said they doubted that Washington would let the state charge anything but nominal co-pays, require employment or walk away from the program.

Because Marketplace Virginia was proposed as part of the Senate budget rather than as a stand-alone bill, the General Assembly will be forced into overtime if budget conferees cannot reconcile their differences by the scheduled end of the session Saturday.

State government would shut down if the matter is not resolved before July 1, the start of the new fiscal year.