A draw here is that they immediately have access to workseekers benefits (apparently - seems the EU forced the UK to make this available recently), the NHS and have the right for kids to be educated in our state schools.
Are though these "rights" available in other EU countries? This is a question which needs to be asked.
Now I've been to Romania and Bulgaria. If I was from there, and was told I would have access to free healthcare, free education, and even if I wasn't working, I'd be paid whilst looking - and I haven't looked into this, but if they can get jobseekers, then surely they'd be eligible for other housing benefits - well it becomes a no brainer.
Go figure!
