Tests carried out by Graham Construction ahead of the launch over the M8 discovered concrete cast in the piers and bases was below industry standards.

The firm will now have to rip out foundations and rebuild the concrete bases delaying the £2.8m contract to install the Hillington footbridge between Renfrew and Arkleston.

The bridge was due to have been installed in March but delays have left it sitting at the side of the motorway.

Work will begin again July but the new bridge is now not expected to be open to the public until September.

A spokesperson for Graham Construction said: “Unfortunately, some concrete supplied during the construction of the bridge abutments was not to the correct specification.

“Thankfully, this was tested before the bridge installation and we are now in the process of replacing the concrete.

“It’s very disappointing that this will cause a delay to the completion of the project, but it’s vital for the local community that we ensure their bridge performs to the highest standards for decades to come.”

Scotland Transerv is currently overseeing the works on behalf of Transport Scotland. Gordon Wilson, contract director, said: “While regrettable, the investigation and concrete testing regimes put in place by the contractor have done their job and Graham Construction will now begin work to remove and rebuild some of the concrete bases and both main span piers before lifting the new steel arch deck into place.”