asked the Secretary of State for Energy what is the estimated revenue from North Sea oil by way of royalties, tax and participation in profits for 1977 and 1978 on the assumption that (a) the £ sterling remains at $1·66 and (b) it is devalued to $1·50; and what would be the savings in foreign exchange in each case.

No such estimates are available. A fall in the sterling exchange rate produces a corresponding rise in the sterling value of our oil and in the foreign exchange benefits expressed in sterling, but of course puts up the cost of imports pro rata.