A union boss insists comments he made suggesting a state politician was “in the gun” were not intended literally, a day after a bullet was found on the Labor minister’s family car.

Victorian Emergency Services Minister and former firefighter Paul Edbrooke said he was shocked and horrified to return to his car on the outskirts of Melbourne on Saturday to discover a bullet lying on the bonnet.

The Frankston MP detailed seeing ”terror” on his children’s faces after informing them of the incident involving the family car they collectively use.

The former United Firefighter’s Union member alleges the bullet, which was inscribed with his firefighter ID number and the word ”rat”, was planted by aggrieved union members.

“The only people I’m really getting aggressive threats from at the moment, and all sorts of rubbish on social media, is members of this union,” Edbrooke told ABC Radio.

Victoria Police confirmed detectives were investigating the incident, which was reported to police on Sunday.

Union secretary Peter Marshall condemned the threat “without qualification” and said the organisation would cooperate fully with police.

”Whoever did this does not speak or act for firefighters or for this union,” he said.

“Threatening anyone, including a minister we strongly disagree with, is the opposite of everything this union stands for.”

However, Edbrooke singled out Marshall’s “violent language” at a Melbourne rally days earlier, in which he said Edbrooke and Premier Ben Carroll were “in the gun”.

“You affect our members, you’re in the gun,” Marshall said in a video posted to the union’s social media on Friday.

Marshall has since clarified he was referring to the ballot box, accusing Carroll’s government of seeking to weaken minimum staffing and employee protections.

“Those protections decide how many firefighters arrive when Victorians call triple zero,” Marshall said.

“This is a safety issue as we are heading into the fire season … We will make that case with votes, never with threats.”

Relations between the union and the Labor government have frayed in recent years over a protracted pay dispute and allegations underfunding is putting firefighters’ safety at risk.

The relationship between Marshall and former Labor premier Daniel Andrews was the central focus of a major investigation by Victoria’s anti-corruption watchdog. It found that Andrews, key ministers and public servants authorised an undisclosed backroom deal with Marshall to resolve a bitter pay dispute in 2016.

The watchdog concluded that by bypassing proper channels, Marshall was given “extraordinary influence” over the negotiations and the state’s firefighting reforms.

Carroll and Opposition Leader Jess Wilson both condemned the incident, with the Coalition leader calling for the temperature to be turned down.

-AAP