Christopher Bakken had been EDF’s project director for Hinkley, leading on its design, licensing, procurement, construction and commissioning since 2011.

He has quit to become executive vice president and chief nuclear officer for US-based Entergy Corporation.

Philippe Bordarier, chief nuclear officer at EDF Energy Generation, who has been with the energy firm for two years, takes over the role.

The news comes after the EDF board postponed taking a final investment decision last week for the nuclear project amid concerns by some of its backers about how it plans to finance the project.

Under current plans, Hinkley Point is due to be completed by 2025.

A decision is now expected to be taken in the next few weeks, to coincide with the release of EDF’s annual results.

EDF said: “Chris Bakken has decided to return to the USA, his home country, to pursue new professional opportunities whilst allowing him to spend more time with his family.”