Sacked CFMEU leaders have vowed to campaign for the “absolute destruction” of the Labor Party and attacked ACTU secretary Sally McManus as a class traitor as construction workers walked off the job to attend huge rallies across the country to protest the union’s administration.

Ousted CFMEU Queensland leader Michael Ravbar will on Wednesday start fundraising for an “urgent” High Court challenge to the administration as other unions pledged to contribute millions of dollars in expected legal costs.