Yes, you can. Ultimately, an employer is not expected to hold your job open indefinitely. However, in order to avoid a potential claim, your employer should still do this fairly and should ensure that you are not subjected to a discriminatory dismissal because you are a disabled person:
Capability to work, which includes lack of capability due to ill health, is a potentially fair reason for dismissal.
As well as being able to show that your capability was the reason for dismissal, your employer will need to follow a fair procedure. This should include:
Other factors when considering fairness will include: the nature of your illness and the prospects of you returning to work; and the effect of your absence on the workplace.
Sometimes an employer may offer you a Settlement Agreement to agree the terms of an exit due to ill health. If you feel you have been dismissed unfairly or have been offered a settlement to exit, do get in contact with us.