West Ham are expected to announce the departure of Sam Allardyce tomorrow.

The Mail on Sunday says a rift between the manager and co-chairman David Sullivan is behind Allardyce's demise.

Allardyce refused to accept vice-chairman/owner David Sullivan's decision last summer to become the club's de facto director of football.

Since then Sullivan, with a football-based advisor, has wrested control of transfer activity and even the desired direction of the team.

That caused a breakdown in relationship between the co-chairman and Allardyce which had been fragile for some time.