BBC News says:
The boss of the controversial HS2 rail link is leaving to take up a senior post at Rolls-Royce, the aerospace and engineering group has said.
Simon Kirby will take up the role of chief operating officer, reporting to chief executive Warren East.
Mr Kirby has earned a reported £750,000 salary at HS2, which will link London with the Midlands and northern England.
He said it had been a "huge honour" to work on the project, which critics say threatens swathes of countryside.
HS2 Ltd said it would miss Mr Kirby's "experience and leadership", while Rolls-Royce boss Mr East said the appointment would "strengthen management capability ahead of a period of significant expansion".
But Stop HS2 campaign manager Joe Rukin accused Mr Kirby of "getting out before the true scale of the mess he has presided over is realised".
"The departure of Simon Kirby will be a serious blow to those who champion HS2, though many of us are at a complete loss to see just exactly what it is he has done to justify his three-quarter of a million pay packet."