I am obliged to the hon. Gentleman for giving me notice this morning that he would raise this matter this afternoon. It gave me an opportunity to prepare a considered statement in reply to his point of order.

There is a long-standing rule of the House that a question may not be tabled if it is already fully covered by an answer or by a refusal to answer. In 1972 the House relaxed the rule, which previously applied for a whole Session, so that information refused in answer to a question may now be asked for again in three months' time.

The Prime Minister has refused to confirm or deny movements through allied bases. Any question on this subject must therefore, be tested against that refusal by the Table Office and, if the question is referred to me, by myself. Obviously I cannot rule on particular questions until I have considered them, and I am sure that the House would not expect me to comment on any hypothetical questions that hon. Members might have in mind.