“At a time when wages are stagnant, and our living standards are slipping, the last thing that Australian working families need is Jacqui Lambie’s personal attempts to blackmail myself, our members and 13 million other Australian workers,” he wrote.
“No politician has the right to dictate who should lead a union … At the end of the day our members want me to stay, so I stay.”
Mr Setka also talked up the strength of the union, which he wrote had grown under his leadership from 23,000 members to 32,000.
“I implore all Australian workers not to be distracted by this well organised personal campaign against me, and instead contact Senators and urge them to reject these extreme workplace laws,” the letter said.
A spokeswoman for Ms Lambie said the Senator had been clear to Mr Setka and the Australian public and would not comment further.
The CFMMEU said it had “no comment” when asked by The Age who paid for the ad.
The enmity toward Ms Lambie stems from her comments that she would only help vote down the government’s union-busting Ensuring Integrity bill if Mr Setka stopped being “a bloody meathead” and resigned.
That call came after a string of high-profile incidents.
Mr Setka was given a good behaviour bond in the Melbourne Magistrates Court in June after pleading guilty to harassing his wife, Emma Walters.
Mr Setka launched an expletive-ridden tirade at a union meeting this month about how “f—ing crossbenchers” would “wear the consequences” if they voted in favour of the bill.
Mr Setka is set to be hauled before a Senate committee to defend the serious allegations, which carry penalties of jail or fines, that the tirade threatened the crossbenchers.
Centre Alliance Senator Rex Patrick has revealed it was also referred to the Australian Federal Police, “who are now looking into the matter”.