What if overcome 183 days ??

[borderreiver]

Just declare the income in the UK as well as Italy, regardless of any 183 day rule. The double taxation treaties mean you will effectively end up paying whichever country's tax rate is higher, which is likely to be Italy anyway (a quick look at wikipedia suggests rates are higher there than the UK).

So you will end up paying no more than if you'd just declared it in Italy anyway. Plus you can sleep easier!