Ok thanks. I do understand the frustration this may have caused you. As far as the legal position is concerned, I would not say you have been doing the job long enough to be able to claim any permanent rights over it, especially if it was not made clear by the employer that they had intended for you to be placed permanently in it. If you did not have any clear indication that the employer wanted you to keep this role permanently (the inferences you mentioned will not be sufficient), you would have had to rely on what is known as ‘custom and practice’ in order to try and lay any permanent rights to it. This is where something has been applied consistently over a period of time, so that it has become an implied contractual term.
Whilst the law does not stipulate a specific period which is required for something to become an implied term, usually we are looking at years rather than months, hence why I do not believe that 9 months is long enough, especially when it was not made clearer by the employer that there was a firm intention on them to keep you in this role permanently.
There is nothing stopping you from leaving and pursuing constructive dismissal, but it will be a difficult claim in this case.
It is worth mentioning that there is a possible alternative solution, where the employer is approached on a 'without prejudice' basis (i.e. off the record) to try and discuss the possibility of leaving under a settlement agreement. Under such an agreement, the employee gets compensated for leaving the company with no fuss and in return promises not to make any claims against the employer in the future. It is essentially a clean break, where both parties move on without the need for going to tribunal. However, it is an entirely voluntary process and the employer does not have to participate in such negotiations or agree to anything. It just means that these discussions cannot be brought up in any subsequent tribunal claim and prejudice either party. So there is nothing to lose by raising this possibility with them as the worst outcome is they say no, whereas if successful it can mean being allowed to leave in accordance with any pre-agreed terms, such as with compensation and an agreed reference.
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