The car was parked with auxiliary power on. I double pressed the start button to shut down the ignition as normal. THEN I lightly pressed the footbrake and pressed the starter button, showing green light, to no effect. Shut down again several times ( ignition completely off) before leaving the car and locking it. Unlocking again, fixed the problem also as advised by the recovery man who was summoned by Eurotunnel as I was holding up disembarkation of the train. UPDATE - Reported the fault to Lexus Canterbury; they requested the car to check it over, FOC. Two days before taking it to garage, car failed to start twice. Fault identified as a partially discharged hybrid pack coupled with a loose hybrid battery connection in the boot recess. Problem seems to be fixed after Lexus recharged the battery pack overnight and tightened the loose connection.