The firm said tower crane drivers currently earn packages worth around £60,000 a year,

Wolffkran added that its most recent offer would mean its 260 crane operators would have received pay increases totalling 19.8% over the last five years.

Director general manager Dave Holder said: “Despite the economic uncertainties of recent years, we have enjoyed high utilisation and rental rates, which have allowed us to perform well.

“This performance has been reflected in the level of remuneration we have passed on to our tower crane operators, whose pay has increased by an average of £7,689.22 since 2013.

“At the same time, agreed pay awards have also led to a decrease in the average number of hours worked per week.”

The latest offer of 3% has been rejected by drivers and the Unite union who are holding a ballot for industrial action.

Holder said: “Industry commentators have said that our pay award for 2017/18 is not just the best in the tower crane rental sector, but one of the best in UK industry this year.

“Therefore, to have it rejected, and be informed by Unite that its members want a 10 per cent increase is both disappointing and more than a little surprising.”

The threat of strike action is already hitting the firm which has lost “two significant contracts from longstanding customers as a result of it.”

Jerry Swain, Unite national officer for construction, said: “It is disingenuous to claim workers have received substantial pay rises in recent years when in reality the company was simply returning money that they had cut from workers’ pay.

“HTC Wolffkran is correct to claim that some crane drivers earn £60,000, however they fail to mention how many hours a week a crane driver would have to work in order to make that kind of money.

“Also the company doesn’t address the physical and mental demands placed on a worker operating in a highly stressful and safety critical environment for such a long period.

“As previously stated Unite remains committed to seeking a negotiated settlement and are firmly of the belief that if HTC Wolffkran is prepared to sit down and enter into meaningful talks, strikes can be avoided.”