To ask the Secretary of State for Defence what is his Department's aim during the negotiations for a comprehensive nuclear test ban treaty. [33160]

Our aim in the negotiations of a comprehensive nuclear test ban treaty is to establish an effective and verifiable treaty commanding universal adherence as soon as practicable.

To ask the Secretary of State for Defence what assessment he has made of whether Britain still has a requirement to use underground testing in order to maintain the stock of nuclear weapons. [33161]

We do not have any current plans for further underground tests of nuclear weapons. However, we are still considering what activities might be necessary to ensure the safety and reliability of our nuclear weapons under a comprehensive nuclear test ban treaty.