Quite true, VHG. That's the problem France faces and it is one of their own making. They signed up to the ridiculous Schengen agreement which effectively abandoned their (already flimsy) borders with other countries, most notably for this purpose, that with Italy. So they have no idea where these people came from (although about 99% of them enter France from Italy). The Italians do themselves no favours because, instead of towing boats full of "refugees" back to the North African coast they actually have a programme to assist them ashore. They are "proud" to be the choice of landing place for these people. Unfortunately they are equally proud of quickly ushering them across their border into France.
We have no such difficulty. When people arrive on board containers and lorries at Dover we know they have arrived from France or possibly Belgium - it is easy to check where the lorry came from - and they should be sent back there forthwith.
The root cause of this problem is mainland Europe's open borders. It was foreseen when the scheme was introduced but nobody listened. The French, Italians and in fact most of mainland Europe are paying the price for this folly. There is no reason why we should help them out of the mire.