Which of the following groups is NOT allowed to stand in general elections?

Peers are not allowed to stand in general elections as candidates for the House of Commons. In the UK, while they hold significant positions in the House of Lords, they cannot contest elections for the House of Commons, which is reserved for elected representatives. This is rooted in the principle of maintaining the distinct roles and functions of the two chambers of Parliament, where the House of Lords is composed of appointed or hereditary members rather than elected ones.

Citizens of the UK who are over the age of 18, Commonwealth citizens with the right to reside in the UK, and certain members of the House of Lords (in some contexts) could all potentially stand for election under different circumstances. However, the inability of peers to stand for election to the House of Commons distinguishes them clearly within the electoral framework.