The budget must agreed by full council so at the point where you do this, assuming you've not already done this, the question has to be asked why the salaries budget appears to have increased by considerably more than inflation? It may be, for example, that provision is being made for an increase in staff? As others have said, the clerk has no authority to "give themselves an increase". It would have to be approved by whoever has authority to do so (possibly a committee if you've delegated authority to a committee for example but otherwise by full council) and in doing so there should be an explanation of how the figure has been arrived at.