Members of Unite, the UK biggest union, working for Hertel UK, at the Teesside oil refinery, are to be balloted for industrial action in a dispute over pay.

According to the union, the company has been notified that workers who provide repair and maintenance services for the global oil giant ConocoPhillips will start voting for strike action or industrial action short of a strike from Friday May 20. The ballot closes on June 1, Unit said in a statement.

The union says the dispute is over the refusal of employers to improve on its zero per cent pay offer for 2016/17 – a decision deemed unacceptable by the union.

Industrial action at the Seal Sands site near Middlesbrough will seriously impact operations causing a possible shutdown of the site, warned Unite.

Unite said it was urging Hertel and ConocoPhillips to sit down and come up with a sensible pay deal that the unions (Unite and GMB) can recommend to members.

Steve Cason Unite regional officer said: “The clock is ticking for Hertel and ConocoPhillips with a real threat of a walk-out unless there is some movement to address our members’ concerns.

“We held a constructive meeting with Hertel’s management team but despite some progress being made, it was made clear that ConocoPhillips would not fund a pay increase.

“Hertel has been told in no uncertain terms that the zero per cent pay offer currently on the table is not something our members are prepared to accept.

“Strike action is always a measure of last resort. All our members want is a fair pay deal, one that that recognises the work that they do. They have already signalled that they are prepared to take action to get pay justice and will not be swayed by the employers’ redundancy threats.

“There is still time to bring this dispute to an end but the ball is now firmly in the employer’s court. We are urging Hertel and ConocoPhillips to sit down and come up with an affordable and sensible pay deal or risk major disruption on the site.”

Unite is seeking an improved pay offer, over three years, linked to NAECI pay rates, of 1.5 per cent in the first year, 2 per cent in the second year and 2.5 per cent in the third year.

ConocoPhillips operates the Teesside terminal, with operations comprising both processing and tanker-loading facilities covering a 307-acre site at Seal Sands, at the mouth of the river Tees.

Crude oil and natural gas liquids from ConocoPhillips’ J-Block and Greater Ekofisk Area offshore fields are delivered to Teesside as well as third party volumes from other areas of the North Sea.