AUGUSTA, Maine — Gov. Paul LePage’s recent comments about workers being forced to join unions drew criticism on Monday from labor advocates who said federal law already protects employees who decline to organize.

LePage made the comment on two separate occasions over the weekend as the administration gears up for a political brawl with labor unions over a “right to work” bill that would curtail the ability of unions to collect dues or fees from nonmembers.

“Forcing a worker to join an organization as a condition of employment runs counter to the rights described in our Declaration of Independence,” LePage said in his Saturday radio address. “For many in Maine there is no freedom of choice when it comes to union membership. I think that needs to change and I look forward to a fair but honest debate on the matter.”

The governor later reiterated that point during an interview with the political news website at the National Governors Association meeting in Washington, D.C. LePage said “fair share” labor practices in Maine mean “you’re required to belong to a union, you’re required to pay dues.”

But labor advocates say LePage has his facts wrong.

While nonunion workers in some states — including Maine — can be required to pay union dues, they cannot be forced to join the union under federal law.

“We think it is unfortunate that he is factually very uninformed on the topic,” said Matt Schlobohm, executive director of the Maine AFL-CIO.

The “freedom of association” clause of the First Amendment to the Constitution grants citizens the right to organize. Several U.S. Supreme Court decisions have held that workers also have the right to not organize — that is, the freedom to opt out of joining a union.

“There can be no so-called forced unionization,” said William Murphy, director of the Bureau of Labor Education at the University of Maine.

LePage’s comments come at a time of heightened tensions between the administration and labor groups.

The governor is a vocal supporter of “right to work” laws that would prohibit unions from requiring that nonunion workers pay dues or service fees.

Defenders of such “union security clauses” insist all workers who benefit from the terms of a collective bargaining agreement should help bear the costs of the union representation that negotiated those benefits.

After all, supporters say, unions are required by federal law to represent all workers — regardless of their status with the organization — when negotiating contracts and in employee grievance cases.

But critics maintain that forcing nonmembers to pay dues or other fees is a violation of worker rights.

“Right to work” laws are on the books in 22 states, and legislation is pending in about a dozen more, including Maine, according to Patrick Semmens, spokesman for National Right to Work Legal Defense Foundation.

Semmens acknowledged that workers are not forced to join unions. But Semmens said employees often are told by union officials that membership is mandatory or are not told they can withdraw later without penalty.

But the bigger question, according to Semmens, is how meaningful “resigning” or withdrawing from a union is when the worker must continue to pay dues, is bound by the terms of the union contract and is prohibited from negotiating his own contract with an employer.

LePage spokesman Dan Demeritt said the governor fully supports workers’ rights to join a union and to collective bargaining, which has been a flashpoint in the pitched political battle in Wisconsin between unionized state workers and Gov. Scott Walker.

Likewise, workers should have the right to opt out of paying union dues, Demeritt said.

“If you think it is in your best interest to organize, you ought to be able to,” he said. “But if you don’t, you shouldn’t have to contribute.”

Opponents of the pending legislation in Maine, meanwhile, contend that even the phrase “right to work” is misleading because they argue such laws undermine unions and the ability of labor and employers to negotiate freely.

“There is a great deal of misinformation about this issue and a lot of distortion,” Murphy said.