Stamp Duty Land Tax (Temporary Relief) Bill

I wonder if the Minister could clarify a couple of points. On the 31 March date, we all worry that this will end up being a cliff edge, as the date approaches. Will that be the date of exchange, which is usual, I think, in these matters? Is he not concerned about that cliff edge? For some people, for no reason of their own, late finishing of their property will mean they fall the wrong side, very expensively?