Is not rocket science though, if they have no national Insurance number, cannot speak the Language and cannot produce a birth certificate that they are not from the UK..
My bone of contention is after processing these illegals, they are often released, pending a decision to dissappear back into the populace.
Personally I would adopt the Aussie practice and house them on an Island off Scotland that is not within swimming distance until they remember where their documents are, and if you come off the back of a lorry off the ferry from France, they should be simply deported back to France as you are not fleeing from any persecution. None of this we will look at their case, they don't have one under EU law.