Premier Jim Prentice assured public sector union leaders Thursday he will not attempt to roll back wages and promised to revoke a controversial bill that restricted union activity and imposed prohibitive fines for illegal strikes.

Bill 45, which passed under former premier Alison Redford but was never proclaimed, was vilified as anti-union and drove a wedge between the government and its employees.

It was passed in December 2013 in response to a walkout of prison guards.

The bill was being challenged in the courts by the United Nurses of Alberta, which called it a violation of their freedom under the Charter of Rights and Freedoms.

Prentice said the bill should never have been introduced or passed in the first place.

He said he hopes with Bill 45 out of the picture, a more respectful tone will be set for labour negotiations.

Prentice made the announcement after meeting with leaders of the Alberta Union of Provincial Employees, the United Nurses of Alberta, Health Sciences Association and the Canadian Union of Public Employees Alberta.

Labour groups have accused the premier of demonizing public sector workers after he repeatedly blamed their contracts for the province's fiscal woes.