Cemex is bracing itself for possible industrial action following a ballot among drivers.

A vote among 74 HGV drivers based at depots in Rugby, Tilbury, Barton-on-Humber and Newport came after they rejected the company’s pay offer, which the Unite union said amounted to a pay cut in real terms.

It warned that there will be project delays if its members back industrial action and said Cemex needed to offer a pay deal which “which better reflects the contribution drivers make to the business or risk a programme of industrial action through the spring and into the summer when construction sites are at their busiest".

Specifically, Unite said action could lead to supplies to Heathrow and infrastructure projects such as the Mersey Gateway being disrupted.

Adrian Jones, Unite national officer for road transport, said: “Members are simply not going to accept a pay offer which in real terms sees their pay fall.

“It is imperative that Cemex understands the determination of our members and produces a much improved offer to avert the need for industrial action.

“If industrial action does occur, then it will severely affect large sections of the construction industry, creating shortages of building materials for key construction projects and cause serious delays.”

He added that the union would formally write to Cemex on 8 May outlining its intention.

Cemex did not respond to requests for comment.