Diess has demanded a contract extension and more backing for his reform efforts from the carmaker's non-executive board, but he has met resistance from powerful directors who represent employees and unions.

The supervisory board meeting was brought forward to Monday from its original date of Thursday.

Diess has sought to lower costs in Germany to free up resources for a mass electrification push, seeking to transform Volkswagen into more a tech-focused company.

Diess and Bernd Osterloh, Volkswagen's chief labour representative, have clashed over key issues including appointments to the management board and whether to extend Diess's contract beyond 2023.

Volkswagen's supervisory board Chairman Hans Dieter Poetsch has been seeking to find a solution to the impasse before Christmas.

(Reporting by Jan SchwartzWriting by Ludwig Burger; Editing by Keith Weir)