Plom took voluntary early redundancy as the organisation cut its 3,584-strong staff, with the last leaving last month. Among those to go were 23 inspectors.
The HSE is awaiting next year's budget before making a decision on replacing Plom. Francis Hirst will now cover amenity for the HSE but the executive will not exhibit at Saltex after reducing its communications budget.
Walker said: "There will be a replacement but there is uncertainty about when." An HSE representative added: "We believe the changes will enable us carry out our role effectively while giving value for money to the taxpayer."