In the most decisive day since the crisis over the appointment of a new director began last November, education director Keith Davies and the director of economic and community development, Tom Williams, were told on Friday to clear their desks by today.
Their replacement is John Ellis, who was education director in the former county of Dyfed. He starts work on Wednesday.
But Mr Davies is considering bringing allegations of constructive dismissal against the council. Mr Williams is also taking legal advice.
She adeed: 'He has a great deal of experience in managing change and will play a pivotal role in developing the council's new service structure, which becomes operational on 1 April.'
A statement from Mr Ellis said: 'Organisational change is never straightforward and there are bound to be some people who feel unsettled and concerned about the future. I see my role as reassuring the council's hardworking and committed staff that this new department will offer the public quality services expected in the 21st century.'
But in an unexpected move, a solicitor, Michael Jones, is being instructed by a group of local taxpayers on pursuing a judicial review of the council's actions.
Mr Jones said the council's decision to appoint Mr Ellis at once meant that it was paying three people for the same£70,000-a-year post.
He said: 'I cannot see what the terrible urgency was to find a replacement for Mr Davies. They already had a director in the post and they intend to appoint a permanent director by June or July. Why not leave him there?'