Andrew Flintham is to return to TUI UK just months after leaving to join rival Thomas Cook.
Flintham had resigned as commercial director of TUI in October and was due to take over the helm at Thomas Cook UK in March.
But following the resignation of Nick Longman earlier this month, Flintham is now going back to TUI as managing director TUI UK & Ireland.
He said: "I am delighted to become the new managing director of TUI UK and Ireland, a role I couldn’t imagine would become available when I resigned the commercial director position a few months ago.
"I look forward to working with such a great team again as we continue to take our business forward."
A spokesman for Thomas Cook said: "Chris Mottershead will continue to manage the UK&I until we have found a replacement. We wish Andrew all the best in his new role."
