Staff operating GoSafe speed camera vans have gone on strike for 24-hours.
They claim they are confined to their vans for up to 11 hours at a time without proper toilet facilities.
Labour Party leader Brendan Howlin has called on Justice Minister Charlie Flanagan to intervene.
He said: "We know that excessive speed is involved in many cases of road traffic death or injury.
"While some people might joke about the speed cameras being out of operation, the sad truth is that over 1,000 people have died on our roads in the last six years, and tens of thousands have been injured.
"Road deaths have decreased due to safety measures being put into place, including speed cameras and enforcement of penalties.
He added: "The problem in this strike is that the employer, GoSafe, is refusing to negotiate with the trade union SIPTU about issues such as low wage staff working 11 hours with no toilet facilities and having nowhere to eat their lunch other than in a cramped van or on the side of the road.
"Charlie Flanagan is washing his hands of the matter, by claiming that GoSafe is a private company.
"The Government should never give contracts to companies that ignore the industrial relations bodies of the state, as GoSafe has done by ignoring a Labour Court ruling that SIPTU is the only valid negotiator on behalf of these workers."
Mr. Howlin said both the Justice Department and the Gardaí are both signatories to this contract.