It doesn’t. The idea of this insurance is to take over when you’re sick pay ends.
Some employers will provide you with your salary for a period of time when you’re ill, with some of the better packages paying you for up to 12 months. Others have little or none, so you should check what your employer will pay you and for how long before taking out protection. The longer you receive the benefit, the longer the deferment period on your pay out can be which can help lower your premium you also need to consider some policies may not pay out if you are still in receipt of your salary.
If you’re self-employed you have no benefits from an employer so Mortgage Protection may be something you consider.