Flags were flying at half mast at the Saskatchewan legislature Monday following the death of federal NDP leader Jack Layton.

Layton died early Monday following a battle with cancer. He was 61.

At the Legislative Building in Regina, flags will fly at half mast until Layton's funeral.

'You couldn't help but admire Jack Layton's spirit'—Saskatchewan Premier Brad Wall

A condolence book for the public to sign has been set up in the rotunda of the legislature, the provincial government announced.

Premier Brad Wall offered condolences in a written statement.

"You couldn't help but admire Jack Layton's spirit," Wall said. "To find the physical and emotional strength to lead a successful national election campaign while fighting cancer — that will be remembered as one of the truly remarkable accomplishments in Canadian politics.

"And his spirit did not waver. Even at his final public appearance last month, he remained optimistic, hopeful and dedicated to public service."

Tireless fight

Saskatchewan NDP leader Dwain Lingenfelter said Layton will be remembered for his tireless fight to bring the concerns of real people into the House of Commons.

"When Jack spoke about homelessness in his own neighbourhood, or about the difficulty of finding quality care for his father in his later years, his obvious sincerity about the real issues facing Canadians came through," Lingenfelter said in a news release.

"People could tell that Jack cared and they responded with their trust, affection and admiration."