broker is just not experienced enough in this.
If you think that get somebody else, i made that mistake in 2006 - with a broker that didnt have a friggen clue - he talked a good story but didnt have a clue, went back a few months later to the same office but spoke to another guy and it couldnt have been more different, we stayed with this guy for the future and also put a few other mortgages through him, this was all during boom times though bare in mind. You need somebody thats commission hungry and can give you the right advice.
With regard to the poor UK credit rating, i think some companies ask for Experian UK credit reports etc.. but not all, unless you provide this i dont see how it can follow you in Poland.
My advice is dont give up easily and speak to a few banks/brokers. and be ready to hand over mountains of paper work.
Ive known of people having good feedback from various institutions throughout the process only to be denied at the last minute, which as you can imagine is friggen infuriating.
100% mortagage pre-approval is something Poland really needs, this whole find a house make an offer and then apply for a mortgage is really annoying.