asked the Secretary of State for Defence what has been the expenditure each year since 1970 on the Chevaline project to update the Polaris warheads; and what expenditure is planned over each of the next 10 years for this purpose.

As I explained in the House on 24 January—[Vol. 977, c. 681–82]—the programme's overall estimated cost totals about £1,000 million. Development is close to completion and expenditure is past its peak.To give any further breakdown would, I regret, give an indication of the timetable of the project which it would not be in the national interest to disclose.