The Legislature’s budget-writing committee advanced an $8.3 billion two-year state budget bill in a series of 8-4 party-line votes Thursday.

The bill, supported only by majority Democrats, now goes to the full Legislature, which will take it up when it meets at the Augusta Civic Center on Tuesday.

Democrats, who hold 23 of 35 Senate seats and 80 of 151 in the House, signaled earlier this week they would pass the new spending plan with or without Republican support.

Republican leaders criticized that move during a news conference Wednesday. They called the Democrats’ budget proposal – a slightly pared down version of a two-year spending plan offered in January by Gov. Janet Mills, also a Democrat – “incomplete” and a “sham.”

Sen. Cathy Breen, D-Falmouth, Senate chair of the Appropriations and Financial Affairs Committee, said it is a basic budget that is largely flat and includes no new spending initiatives from lawmakers or Mills. It also calls for no new tax increases, Breen said, noting that a provision that would have added a 6 percent sales tax to online streaming services was removed after Republicans objected to it.

The move by Democrats to pass a majority budget is a departure from the last several state budgets, which have been passed with bipartisan support by more than two-thirds of the Legislature. That allows the bills to be enacted as emergency laws that go into effect immediately. But the Legislature has passed majority budgets previously, most recently in 2005.

To pass the budget without Republican support, the Legislature will have to approve it before the end of the day on March 31. That would provide the 90 days required by the state Constitution for the bill to become law before June 30 without the emergency preamble.

The committee vote Thursday all but guarantees that Democrats will be forced to vote to adjourn the Legislature next week to start the 90-day countdown in time for the bill to become law by June 30. Senate President Troy Jackson, D-Allagash, said earlier in the week the Legislature would adjourn if it can’t muster the two-thirds majority needed to pass the budget as an emergency measure.

Democrats have said passing the budget early is important, not only to state government but to town and city governments and public schools, which all base their local budgets on state revenue allocations dictated by the two-year budget.

Pushing the budget debate to the end of the fiscal year risks another government shutdown and would be a blow to Maine businesses, especially those that cater to the summer tourism industry, which will be in full swing by late June.

Republicans on the budget committee expressed disappointment again Thursday, saying their voices were being left out of the budget-writing process and that a majority budget would not reflect the wishes of all Maine residents.

“At a time when we should be meeting openly and transparently, some have been quietly crafting a budget with the intent to bypass the voices of a cross section of Mainers, going forward without their peers,” Rep. Patrick Corey, R-Windham, a member of the committee said.