The contractor has returned loads of ready-mixed concrete that had time-expired while being delivered from a batching plant specially set up at a nearby landfill site for planned big pours.

Over two weeks alone, 40-minute traffic delays on part of the route hit deliveries causing around £22,000 worth of concrete to be condemned.

Now supplier Hanson is calling on local planners to allow deliveries to be re-routed through the quiet Oxfordshire village of Sutton to avoid further costly delays.

Hanson warns that delays on the A40 heading into Oxford due to roadworks on the Cutteslowe and Wolvercote roundabouts could put the construction programme at risk.

Concrete containing additives to delay the concrete going off have not been accepted by the project team.

Hanson has pledged to limit deliveries on the alternative route to 21 trucks a day between 9am and 3pm to avoid school run traffic.

Despite local opposition planners look set to agree the rerouting plan on Monday on grounds of sustainability.

The new plan would address the current problem of concrete loads being returned to the site, which was resulting in unnecessary traffic on the highway network and wastage.

But the planners report said the justification for also allowing returning empty lorries to use the route is less clear.

The £440m development in the heart of Oxford city centre will transform the existing Westgate shopping centre into an 800,000 sq ft retail and leisure destination, due for completion in autumn 2017.

Laing O’Rourke’s 30-month contract is focused on the construction of the shell and core of the three-storey retail centre, together with a 1,000 space underground car park and 61 new residential properties.