Under the Representation of the People Act 1981 any MP sentenced to over a year in jail automatically vacates their seat.
To be eligible to stand as an MP, a person must be at least 18 years old and be a citizen of the UK, a Commonwealth nation, or Ireland.
[8] Additionally, members of the Senedd (Welsh Parliament) or the Northern Ireland Assembly are also ineligible for the Commons according to the Wales and Northern Ireland (Miscellaneous Provisions) Acts respectively, passed in 2014 (but members of the Scottish Parliament are eligible).
[7] The Representation of the People Act 1981 excludes persons who are currently serving a prison sentence of a year or more.
These offices are sinecures (that is, they involve no actual duties); they exist solely to permit the "resignation" of members of the House of Commons.
The Chancellor of the Exchequer is responsible for making the appointment, and, by convention, never refuses to do so when asked by a member who desires to leave the House of Commons.
[11] The first duty of a member of Parliament is to do what they think in their faithful and disinterested judgement is right and necessary for the honour and safety of Great Britain.
All these three loyalties should be observed, but there is no doubt of the order in which they stand under any healthy manifestation of democracy.Theoretically, contemporary MPs are considered to have two duties, or three if they belong to a political party.