Being taxed as an EU citizen (when working in Poland)?

Can someone explain to me how does this work? I'm from the UK and I will start work here in Poland in September. I called the local tax office and they said I need to go to Gdańsk to register myself but I won't be taxed by the Polish Government. Instead I need to inform the English government that I am working here and THEY will tax me. How does this make any sense? Am I going to be taxed an insane amount?

How long will you work in Poland?

That makes a big difference.

I have heard something about the 183 day thing, but I haven't signed an official contract yet so I cannot be sure 100% of my hours, but I will have maybe 20 hours a month. The contract will be for at least one year.

Are you working as a contractor through a your own/management company or will you be directly employed?

That's the 183-day residency rule. However - to avoid any potential hassle with the Polish tax office, I'd advise you to simply go through the Polish tax system - it makes life much easier and you won't fall foul of any tax law in the process.

In general though, if you're working here until June/July, then you want to go through the Polish, not the British system.

Thanks for the help, I just found out that I will send off a p85 form and will not have to pay any uk tax

I thought it depends on your place of residence. Delph correct me if I am wrong.
EU legislation says you pay taxes and social insurance in the country where you officially reside.
I reside officially and in reality :) in Poland but have a split contract (Belgian / Polish). For the Belgian part I get paid everything (including the employer's part) and I have to transfer that part and to ZUS and to US. Complicated affair because every month the amount differs.