Materials shortages may cause delays on construction sites such as at Heathrow and the Mersey Gateway crossing after HGV drivers at Cemex voted for industrial action in a wages dispute.

The 82 participating drivers, who are members of trade union Unite, will begin a continuous ‘work to rule’ on 22 May followed by an initial 24 hour strike on 26 May.

The drivers supply construction material including cement across the UK and are based at four depots: Rugby in Warwickshire, Tilbury in Essex, Barton-on-Humber in north Lincolnshire and Newport in south Wales.

The strike action comes after the drivers were reportedly offered a 1.6% increase in pay. “Cemex was warned that members were never going to accept a pay offer which was effectively a real terms pay cut,” said Unite national officer for road transport Adrian Jones.

“If Cemex doesn’t act and this dispute goes ahead it will create chaos throughout the construction industry. Sites will swiftly run out of materials which will create delays throughout the entire project.”

He added: “Cemex still has time to avert this dispute by returning to the negotiating table and making an offer which meets our members’ expectations and properly rewards them for their skills, dedication and hard work.”

Work to build the new six lane, cable stayed Mersey Gateway bridge is expected to complete this autumn. Current construction activity includes efforts to install sections of bridge deck and deliver the structure’s north and south approach viaducts.

The industrial action is also expected to affect maintenance works being carried out across Heathrow Airport according to Unite. However Heathrow said it had been assured by its suppliers that its operations would not be affected.

A statement from Cemex said: “We have robust contingency plans in place to manage any industrial action, and will ensure a continued supply of bulk cement to all of our customers. Supply of all other Cemex UK products is not affected.”