Photo: The Canadian Press - file photo

Prime Minister Justin Trudeau congratulates Scott Brison as he is sworn in as president of the Treasury Board during a ceremony at Rideau Hall in Ottawa.

The federal Liberals say they'll roll back changes to public-sector bargaining brought in by the previous Conservative government.

Treasury Board President Scott Brison says in a release that portions of the 2013 omnibus budget bill will be formally repealed with new legislation when Parliament returns from the summer recess next fall.

The Conservative changes allowed the government to unilaterally decide which employees offered essential services and therefore determine who was allowed to strike.

The 2013 bill also made salary arbitration dependent on the government's budget priorities, curtailing the independence of the process.

Public-sector unions promised a constitutional challenge to what they said was an attack on collective bargaining.

The Liberal government has already introduced legislation to repeal two other controversial Conservative-era labour bills that would have forced all unions to publicly disclose their internal financial workings and changed the process for union certification and de-certification.

"By restoring fair and balanced labour laws, the government is recognizing that labour unions play an important role protecting workers' rights and strengthening the middle class," Brison said in a news release Wednesday.

"As another important step in rebuilding the relationship with Canada's public service, we are moving to repeal changes to the public service labour relations regime brought into law by the previous government."