Just to update you on the Polish worker theme. I work for the Civil Service & for the past 2 years, I have interviewed overseas workers here in the UK for National Insurance Number applications.
Poland has been an EU member since May 2004, therefore ANY polish national may live/work here in the UK with NO other restrictions other than applying to the Home Office for the Worker Registration Scheme costing £50.
After 12 months continuous employment here in the UK, that person will then have the right to apply for a Residence Permit exercising their EU treaty rights.
There is nothing ILLEGAL about EU residents working here - They have the same rights as UK nationals working anywhere in the EU.