The UK plans to exile Dmitry Lima to Portugal, on account of a sentence for nonviolent crimes. This despite the fact that he was born in the UK and has never been outside the UK.

I wonder whether Portugal would admit him. Has it got legal grounds to block the deportation?

Since his parents were/are Portuguese, I suppose he is or at least was entitled to apply for Portuguese citizenship — but does he actually have that citizenship? Would it be granted under these circumstances, if he does apply? What if he (rationally) declines to apply for this help in deporting him?

Perhaps this is simply yet another example of the UK state's lack of capacity to implement its own rules reliably.