Tweedy has been at Platform since it formed in 1999.
A spokesman for Platform says: “David Tweedy is temporarily seconded to another role within The Co-operative Banking Group and therefore Lee Gladwell has assumed responsibility for Platform on an interim basis..”
It is believed he has been seconded to a role within the bank to help with its acquisition of the Lloyds Banking Group branches.
Last month the Co-operative Bank announced that it was placing 80 staff at Platform in consultation.
The bank is closing Platform’s London office in Canary Wharf and relocating the departments to other locations, primarily in Manchester.