The hospice cared for 341 bereaved families last year

The service organised by the Sir Michael Sobell House Hospice, Oxford, to commemorate those who have died in its care, takes place on 29 April.

But the Oxford postal strike is in its third week and staff fear the invitations have not been delivered.

Almost four million items of mail are estimated to be undelivered.

The strike began over claims of bullying at Oxford's main Cowley depot.

All those who lost a relative at the hospice are welcome to attend the service.

The hospice offers care and support to people with cancer and other life-threatening conditions, and to their families and others close to them.

Staff say last year there were 341 families receiving help from their bereavement service.