Law / Urgent: Polish work permit, require to travel UK for temporary assignment for period of more than 6 months [2]

Hi I am an Indian national and currently employed and living in Poland with 3 years resident permit Karta Pobyuto which is ending in 2019 I have to travel to UK in April17 for an assignment for the period of 6 to 9 months for which I have to apply for UK work permit though the customer for which I am travelling to UK is of the same company and also we have a branch of same company in UK as well now my concern is if I travel to UK with UK work permit would there be any problem with my current Polish work permit or resident status as I have to come back to Poland after finishing my assignment, also from tax obligation perspective how should my payroll look like in UK, I work in UK on perdiem as I am currently on Polish work permit and employment.

Please help

Thanks