Accenture has been selected to run the London 2012 Olympics back office IT systems on the same day the chief construction manager said politics drove him away from the project.

Jack Lemley, the American engineer drafted in to oversee the building phase of the Games has been widely reported as saying fears of overspending and political wrangles led to his departure two weeks ago.

The former chairman of the Olympic Delivery Committee, who also oversaw the Channel Tunnel project, told US newspaper, the Idaho Statesman that he felt it was better to come home, than face recriminations over escalating costs in five years time. He had pledged only two months ago to avoid a repeat of the Wembley construction problems.

"I went there to build things, not to sit and talk about it, so I felt it best to leave the post and come home," he said.

Meanwhile the London Organising Committee for the 2012 Olympic Games and Paralympic Games announced it had chosen Accenture to run its ‘back office’ systems.

The IT services provider beat BT Global Services, IBM and LogicaCMG to the contract to support integrated planning systems across functional areas and operations, including finance and accounting, the London 2012 workforce and procurement. But it will not cover core Games management systems that relay results, events and athlete information to spectators and media around the world at Games time.

Another provder, Atos Origin is providing the Games IT systems. As the lead IT system integrator, it is responsible for the design, build and operation of the Games IT infrastructure.

The Sports minister, Dick Caborn is reported to have said the Games were on schedule last night.