Oil refinery workers on Humberside yesterday overwhelmingly voted to continue grassroots strike action — but union reps have been denied access to the site.

Five to six hundred workers downed tools at the Humber Refinery at South Killingholme, near Grimsby, and walked out on Monday lunchtime amid safety fears.

Workers had raised concerns following a gas leak and the injury of two workers last week, which prompted a stoppage at the site.

But they said employers had failed to address their grievances.

The workers are employees of contractors BIS Industrial Services, Doosan Babcock, Fabricon and Deborah Services Ltd, who carry out work on the site on behalf of its owner Phillips 66.

On Tuesday morning, following a meeting with managers, the workers voted to continue their strike for another day.

A spokeswoman for Phillips 66 said: “The safe and orderly operation of the facility has not been impacted by this action.

“Phillips 66 has been in ongoing dialogue with contractor management over the last week to discuss the workers’ concerns over onsite communications, and we will continue to work with them to reach a satisfactory conclusion.”

Phil Whitehurst, GMB national officer for engineering construction, said: “Following a major stoppage of work we have been advised that there is a major health and safety issue on the site.

“GMB has been refused access to the site in order to resolve what has been described to us as a major hazard.

“We urge the company to allow the union onto the site to try to resolve the issue as quickly as possible for the safety of workers and the public.”

The workers will hold a further mass meeting today to decide on their next steps.