No, if an employee decides to bring the employment relationship to an end they can dictate the date on which that termination will happen. The contractual notice period is simply the minimum amount of notice the employee should give. If you want the employee to leave earlier, you will still need to pay them up to and including the termination date they gave you. If an employee resigns and leaves without giving you the required amount of notice, can you make a deduction from their pay?
If an employee gives more notice than they are required to give according to their contract, can you require them to leave earlier?
If an employee resigns and leaves without giving you the required amount of notice, can you make a deduction from their pay?
Unfortunately not! If an employee leaves without giving you sufficient notice, they are in breach of contract, but you would need to pursue this through the courts. Even then, you would only be entitled to receive compensation for any losses incurred as a direct result of the employee leaving early which, depending on their role in your company, may be very little or none.
If an employee resigns part way through a disciplinary hearing that may lead to their dismissal, can you refuse to accept it?
An employment contract can be brought to an end by either party; the other party cannot refuse to accept it. You cannot refuse to accept a resignation any more than an employee could refuse to accept that they have been dismissed. If you are part way through a disciplinary hearing, the thing to find out is whether the employee is resigning with immediate effect or whether they are giving you X weeks/months notice. If they are giving you notice you will probably want to continue with the hearing, whereas if the resignation is with immediate effect then their employment comes to an end immediately and there is no need to continue.