asked the Minister of State for Defence if he will make a further statement on the progress of sea trials of the Harrier; and when he will be in a position to announce the order for up-rated Harriers for the Royal Navy.

I would refer my hon. Friend to Chapter II of the Statement on the Defence Estimates 1972 (Cmnd. 4891) which describes the studies that are now being made. Decisions will be taken when these studies are complete.

Does not the Statement on the Defence Estimates show that the present Harrier is not wholly suitable for operations at sea? Since it will be a long time before we can have up-rated Harriers and in view of the increasing Soviet maritime threat and the missile gap, will my hon. Friend retain H.M.S. "Eagle", which represents 50 per cent. of our naval sea power, until at least a replacement ship is available at sea?

I do not think the retention of H.M.S. "Eagle" depends on V/STOL at sea. This matter can be discussed fully next week.

What estimate has been made of possible export orders for a maritime version? Will the Government look at the possibility of collaborating on development costs with the United States Navy, which has expressed an interest in the maritime version?

Collaboration with America is one of the possibilities we have very much in mind. The export opportunities for the Harrier are very great, but I have no detailed estimate.