What are by elections?
By elections are elections that take place between .
The most famous by elections are those occuring for seats to the House of Commons, but they also occur regularly at local government level.
On polling day, parliamentary by elections follow the same procedure as they would in a in relation to rules, hours, the , and the counting of ballot papers.
How many by elections take place during a typical parliament?
Since the 2019 , some 10 MPs from a total of 650 have been elected at a subsequent .
The number of by elections occuring each parliament varies depending on circumstances and the length of the parliament in question.
Between the 2017 and 2019 , there were just 5 by elections.
Between 2015 and 2017 there were 10 by elections.
Between 2010 and 2015 there were 21 by elections.
Between 2005 and 2020 there were 14 by elections.
What causes by-elections?
An MP’s seat can become vacant between general elections for a number of reasons.
An MP Resigns
Firstly a by-election is cause if an MP resigns.  If an MP steps down before a general election there is a formal process by which the Chancellor of the Exchequer appoints them to the office of Crown Steward and Bailiff of the Chiltern Hundreds or of the Manor of Northstead, allowing them to formally resign their responsibilities as an MP.
This procedural device dates from a 1624 Resolution stating that MPs are forbidden from directly resigning their seat.
This was during a historical period in which service as an MP was viewed more as an obligation rather than a coveted profession, meaning that resignations were not encouraged unless absolutely necessary. Prior to the 1500s it was rare for parliamentary sessions to exceed several weeks per year.
Until a new MP is elected the neighbouring MP has responsibility for representing the vacant seat.
An MP dies
On the death of an MP, his or her seat becomes vacant, and a by elections follows.
An MP is declared bankrupt
MPs who are declared bankrupt are not allowed to sit in parliament, and a by election then follows.
An MP is convicted of a serious criminal offence
MPs who are convicted of a serious criminal offence, involving imprisonment of more than a year, are disqualified from Westminster leading to an automatic by election.
An MP accepts a peergage in the House of Lords
MPs who are appointed to the House of Lords cannot continue to serve as an MP. Prior to the reform of the House of Lords, this used to be a particular issue when an MP suddenly became a hereditary peer after the death of a parent.
An MP is ousted by a recall petition
If a recall petition is signed by 10 per cent of electors in the relevant local constituency, a by election is held.
Recall petitions were introduced in response to the 2010 MPs Expenses Scandal. They are now possible when an MP had been imprisoned (for however long) and has had all their appeals exhausted.
Recall petitions are also possible if an MP is suspended from the House of Commons for over 10 days following a recommendation of the Committee of Standards; or if an MP was convicted of making a false Parliamentary allowance claim.
How are by elections called?
When it is decided that a by- is to take place, the chief whip of the party of the ‘s MP “moves the Writ”.
This means they submit a motion asking that ” the Speaker do issue his Warrant to the Clerk of the Crown to make out a new Writ for the electing of a Member to serve in this present Parliament for the constituency of …. in the room of…”
The speaker then asks MPs whether they agree to the motion. If they agree to the motion it becomes an Order for the Speaker who henceforth issues a Warrant to Crown’s Clerk who forwards the Writ to the Returning Officer.
The fresh Writ is usually issued within three months of the vacancy. A by- must take place within 21 and 27 working days from this.
If one is vacant close to a it is customary to leave it so, until it can be filled at the coming . If there are numerous vacant seats by-elections can be scheduled for the same date.
Does the government always lose by-elections?
The government does not always lose by-elections, however voters may behave differently at by-elections to general elections. During by-elections turnout is often lower, likely because voters see the as less important.
Given the focus on a single constituency, local issues may also loom larger in voters’ considerations. By-elections also often offer an advantage to parties not in government as they can be used as an outlet for “protest votes” ahead of a .
Over the last forty years the party has regularly won seats in the English shires from the .
By election results in this parliament
Previous election results occuring in by elections during the current parliament are listed below:
| Constituency | Date of election | Previous MP’s Party | Previous MP | Winner | Winner’s party |
| Tiverton and Honiton | 23 June 2022 | Neil Parish | Conservative | Richard Foord | Liberal Democrats |
| Wakefield | 23 June 2022 | Imran Ahmad Khan | Conservative | Simon Lightwood | Labour |
| Birmingham Erdington | 3 March 2022 | Jack Dromey | Labour | Paulette Hamilton | Labour |
| Southend West | 3 February 2022 | David Amess | Conservative | Anna Firth | Conservative |
| North Shropshire | 16 December 2021 | Owen Paterson | Conservative | Helen Morgan | Liberal Democrats |
| Old Bexley and Sidcup | 2 December 2021 | James Brokenshire | Conservative | Louie French | Conservative |
| Batley and Spen | 1 July 2021 | Tracy Brabin | Labour | Kim Leadbeater | Labour |
| Chesham and Amersham | 17 June 2021 | Cheryl Gillan | Conservative | Sarah Green | Liberal Democrats |
| Airdrie and Shotts | 13 May 2021 | Neil Gray | SNP | Anum Qaisar | SNP |
| Hartlepool | 6 May 2021 | Mike Hill | Labour | Jill Mortimer | Conservative |
