As long as you pay your taxes I couldn't care!! (I'm sure you do, by the way!!!)
If you have an accountant it's something they would probably be able to answer as they know your circumstances. If you decide on the self employment route (if you're allowed) you'll need an accountant or risk giving too much tax to HMRC. If you decide on PAYE you'll pay more tax on your income but won't need to spend hours with HMRC or pay an accountant. With self employment you can set off many expenses against your income and, thus, lower your tax liability.
The taxman likes many sources of income for self employment (ie several customers) otherwise they treat you as an employee.