AUGUSTA, Maine — Tensions rose in the state Senate Thursday as lawmakers sparred over a Republican effort to consider a contentious labor union bill in the final weeks of the legislative session.

Following the lead of the House, the Senate voted largely along party lines to send a bill dealing with public sector unions and non-union state employees back to committee for a public hearing after many thought the politically divisive issue was dead for the year.

Scheduled for Thursday, June 2, the hearing in the Labor, Commerce, Research and Economic Development Committee will take place just six days before GOP leaders hope to complete work for the year and 13 days before the Legislature’s statutory adjournment.

But the tight timeline and high emotions surrounding the so-called “right-to-work” issue have combined to generate additional partisan friction as lawmakers enter crunch time on the budget — friction evident during the Senate debate.

“I think if we bring this one back up we jeopardize the budget in its entirety,” said Sen. Nancy Sullivan, D-Biddeford.

Such suggestions garnered a fiery response from Senate President Kevin Raye, however.

“If issues that divide us … are going to be a litmus test on whether or not we can pass a budget, then all of us have failed,” said Raye, R-Perry. “This is not about the budget.”

The “right-to-work” issue focuses on whether employees at unionized workplaces should be required to pay fees even if they choose not to join the union.

The bill slated for a hearing and debate in the Legislature, LD 309, is no longer a true “right-to-work” bill, according to supporters. That is because, unlike another bill still in legislative limbo, LD 309 only deals with state employees, not workers in the private sector.

Specifically, LD 309 would end the practice known as “fair share” in which the state deducts “service fees” from state employees who opt out of the union. Those fees are intended to cover the costs of bargaining and grievance representation provided by the union — services the unions claim benefit all employees, regardless of whether they join.

But the Republican backers do not think that the “fair share garnishment” should be automatic year after year. Instead, they argue the issue should be negotiated as part of collective bargaining between the union and administration officials.

Roughly 26 percent of state employees currently pay the service fee because they are not members of the two major unions, the Maine State Employees Association and the American Federation of State, County and Municipal Employees.

“This does not impede the unions’ ability to collectively bargain,” said Adrienne Bennett, spokeswoman for Gov. Paul LePage, who supports the bill as well as ending mandatory union fees in the private sector.

The governor is willing to put off that bigger fight, however.

“Right-to-work is an important issue,” Bennett said, “but that is going to come up next session.”

Democrats suggest that LePage’s fingerprints are all over the push to revive LD 309 so late in the session, however. And they have accused LePage of pushing the “fair share” issue as the administration prepares to begin bargaining with the unions.

“This bill could be perceived by outside interests as being an attempt to inject this piece of legislation into the collective bargaining process,” said Sen. Barry Hobbins, D-Saco. “Quite frankly, if there was an attempt to do so, in my humble legal opinion, it could warrant a look by a court as an unfair legal practice.”

It is unclear whether the right-to-work or “fair share” issue will affect the GOP leadership’s ability to gain the Democratic support needed to pass a budget.

Following Wednesday’s heated debate on the House floor, the Democratic members of the budget-writing Appropriations Committee refused to meet with their Republican colleagues.

By Thursday, however, the committee was back at work as they attempt to resolve the major sticking points in the $6.1 billion budget. Among them are proposals to require state employees and retirees to pay more toward their pensions.

Rep. Peggy Rotundo, a Lewiston Democrat who is the ranking member on the Appropriations Committee, acknowledged it is difficult to talk about pension reform when a bill targeting the state employees’ union is raising partisan tempers.

“But we have a job to do,” Rotundo said Thursday. “We don’t have a lot of time left.”

Likewise, Sen. Richard Rosen, the Republican co-chairman of the committee, said spirits were good on the panel despite the right-to-work debate.

“I think we are really disciplining ourselves to stay focused on our work,” said Rosen, R-Bucksport.