Will there be problems with tax when transferring money from the UAE to Polish bank account (held for over 6 years) ?
i) money was taxed in the UAE and
ii) there is a valid double taxation agreement between Poland and the UAE and
iii) the Polish tax office do not assess that your 'centre of vital interests' over the past three years was not actually Poland,
you don't owe any tax on that money.
However, you really
should take professional advice on this.
you would be beter to transfer it to your british account and then to your polish account
How would that have any effect at all (other than forcing the OP to pay for two transfers instead of one)?