§ Mr. David Howellasked the Chancellor of the Exchequer whether he will give an approximate estimate of likely total North sea oil revenues for 1986–87 on the assumption of a crude oil price per barrel of $10, $15, $20 and $25, on the basis of an exchange rate of $1.35 to the pound; and whether he will give the same figures on the basis of $1.30, $1.25 and $1.20 to the pound.