A union made claims against a building company because it was prejudiced against Irish workers, an inquiry has heard.

A construction boss says a trade union drove a “racist” campaign against his company because it had Irish staff and workers.

Eoin O’Neill told the union corruption royal commission that officials of the Construction, Forestry, Mining and Energy Union (CFMEU) forced his company, Lis-Con, out of Queensland by warning contractors not to use it.

Mr O’Neill, formerly the manager of Lis-Con, denied under questioning from counsel for the CFMEU John Agius that the reason the company did not get work in Queensland was a $4 million state payroll tax liability.

“We paid our payroll tax and continued,” he said on Monday.

“Their officers went around to every job in Queensland and told companies not to use us because we didn’t pay super, we carried illegals and we used dodgy Bluecards (safety training cards).

“Plus there was a small bit of racism there because we were Irish.”

Mr O’Neill, who moved to Australia from Ireland 18 years ago, said union officials had stickers on their hats saying “F*** off we’re full”.

“You can take that to mean anything you like but that is anti-immigrant,” he said.

Mr Agius asked Mr O’Neill if he was aware that the CFMEU commonly used the Eureka flag as a badge, and that many participants in the historic Eureka uprising were Irish.

“I am but the CFMEU seem to have forgotten about that,” Mr O’Neill told the commission.

Mr Agius then asked whether any “F*** off we’re full” slogans might have been worn by locals disgruntled about fly-in labour being used on remote construction sites, rather than being worn by the CFMEU.

Mr O’Neill, who still works for Lis-Con as a consultant, disagreed.

He also denied that his company had used Irish backpackers as “sham contractors” on labouring jobs in Queensland.

Mr O’Neill told the commission previously that Lis-Con had been targeted by the union after refusing to make corrupt payments.

He told the commission CFMEU officials told him “we expect to be taken care of”.

Mr O’Neill denied his company required Irish backpackers to operate as private contractors in order to avoid paying them superannuation and other entitlements.

He said union officials had raised the issue of unpaid superannuation but he dismissed the claim as “propaganda” and said the company had received no complaints from workers.

The commission is investigating allegations the CFMEU used member information improperly obtained from its associated industry superannuation fund, Cbus, to target Lis-Con employees during a campaign against the company.

The Royal Commission into Trade Union Governance and Corruption will continue sitting in Sydney on Tuesday.