Work on Google’s planned £650m headquarters at King’s Cross in London could be delayed for another three years, the boss of the contractor appointed to build the scheme warned yesterday. In its annual report released yesterday, BAM Construct chief executive Graham Cash said it was “disappointing” that the building has been pushed back to “at least 2017” after Google went back to the drawing board with its plans. It expects the project to be put back out to tender again when plans have been revised.