Andy Burnham and Makerfield: Can a mayor be an MP?

On 14 May 2026, Josh Simons, MP for Makerfield, resigned his seat in the House of Commons, triggering a by-election. Mr Simons stated that he had done this to give Andy Burnham, the mayor of Greater Manchester, an opportunity to stand for election to the House of Commons. The by-election will take place on Thursday 18 June 2026.

Andy Burnham was confirmed as the Labour Party's candidate on 19 May. Nominations for the by-election will close on 26 May 2026 (see the Library briefing By-election timetables).

This briefing sets out the legal position and processes for a strategic authority mayor to become a Member of Parliament.

Can the mayor of Greater Manchester also be an MP?

The mayor of Greater Manchester is prohibited from being an MP. This is because this mayor is also the Police and Crime Commissioner (PCC) for Greater Manchester.

A strategic authority mayor does not have to resign to stand for election as an MP, only if they are elected. If the mayor fails to be elected to the House of Commons, they will continue to be the mayor.

Section 67 of the Police Reform and Social Responsibility Act 2011 states that if a mayor with PCC powers becomes an MP, they are automatically disqualified as mayor (see also article 3 of the Greater Manchester Combined Authority (Transfer of Police and Crime Commissioner Functions to the Mayor) Order 2017).

The Electoral Commission’s guidance for metro mayors with PCC responsibility says:

If you are successfully elected as the combined authority mayor of Greater Manchester or West Yorkshire and you subsequently become a member of the House of Commons, the Scottish Parliament, the Senedd, the Northern Ireland Assembly or any legislature outside the UK, you are automatically disqualified from holding office as a combined authority mayor and the office of combined authority mayor would become vacant.

The winning candidate, in a general election or by-election for the House of Commons, becomes a member of the House of Commons immediately when the returning officer declares them to have won the election. This would mean that a mayor with PCC powers would immediately cease to be mayor as soon as they won a seat in the House of Commons would.

Can a strategic authority mayor also be an MP?

Yes, currently. This is due to change at the end of June 2026.

Section 17 (5) of the English Devolution and Community Empowerment Act 2026 states that, if a strategic authority mayor becomes an MP, they must resign their position as mayor within eight days of being elected to the House of Commons.

Section 17 does not come into force – that is, it is not yet law - until 29 June 2026 (see section 108 (5) (f) of the 2026 act). This means that it will not apply for the Makerfield by-election.

What happens after a mayor is elected to the House of Commons?

In the short term, the deputy mayor of Greater Manchester takes over until a new mayor can be elected.

Between the point at which the seat becomes vacant and a mayoral by-election, the statutory deputy mayor of Greater Manchester must become the acting mayor (see section 107C (5) of the Local Democracy, Economic Development and Construction Act 2009). The statutory deputy mayor is Paul Dennett. Mr Dennett is a member of the Greater Manchester combined authority and also directly elected mayor of Salford City Council.

How does a mayoral by-election work?

If Andy Burnham were to win the Makerfield by-election, the office of mayor of Greater Manchester would become vacant immediately.

A mayoral by-election must take place by a maximum of 35 working days after the office of mayor has been vacated (The Combined Authorities (Mayors) (Filling of Vacancies) Order 2017, articles 4 and 6). If the by-election is held on 18 June 2026 and Andy Burnham wins the seat, a mayoral by-election would have to be held by 6 August 2026.

The successful candidate in a mayoral by-election would hold office until the next scheduled election for the mayoralty, in May 2028.

A sitting MP would be free to stand in a mayoral by-election. In this case, if a mayoral by-election takes place, section 17 of the 2026 act, described above, would be in force. That section states that a sitting MP who becomes a strategic authority mayor has eight days to resign their seat in the House of Commons. If they do not do so, they are disqualified from being the mayor, and a fresh by-election would have to take place.

Which voting system would be used in the mayoral by-election?

Currently, mayoral elections use the ‘first-past-the-post’ voting system.

Section 63 of the English Devolution and Community Empowerment Act 2026 provides for mayoral elections to take place using the supplementary vote (SV) system. Section 63 is not yet in force. The government must bring it into force by a statutory instrument.

The government laid a statutory instrument before Parliament on 21 May 2026 to reintroduce the SV system as of 19 June 2026. In a written statement it said that "It was the clear intention of the Government, as stated during parliamentary passage of the Act, that this return to Supplementary Vote would be implemented ahead of any future relevant elections after May 2026". This would mean that SV would be in place for any mayoral by-election after the Makerfield by-election takes place.

Bringing the supplementary vote system into force in that timescale would go against the ‘Gould principle’. This is a convention that changes to electoral law and practice should not impact any elections for six months after the change has been introduced (see the 2007 Gould Report, pages 18 and 111). This convention has not always been observed rigidly.

Have other mayors been MPs?

Prior to 29 June 2026, there is no prohibition on an individual being elected as, or holding office as, a combined authority mayor (or Mayor of London) and an MP at the same time.

Individuals who have been mayors and MPs at the same time are Ken Livingstone (2000 to 2001), Boris Johnson (2015 to 2016), Dan Norris (2024 to 2025) and Dan Jarvis (2018 to 2022).

MPs who are elected as PCCs cannot sign the declaration of office as PCC until they have given up their seat in the House of Commons (under section 70 of the Police Reform and Social Responsibility Act 2011). If elected, they have two months from the date of election to sign the declaration of office – and therefore to stand down from the House of Commons. Tracy Brabin was required to do this when elected as mayor of West Yorkshire in 2021.

When Andy Burnham was elected as mayor of Greater Manchester in 2017, he had been an MP until the day before the mayoral election. At that point Parliament was dissolved because of the snap 2017 general election, in which he was not a candidate.

The disqualification provision in the 2026 act does not apply to members of the House of Lords. One current mayor, Lord Ben Houchen (Tees Valley), is a peer, and is not affected by section 17 of the 2026 act.

The disqualification provision also does not apply to local authority directly elected mayors, who may still hold office as MPs at the same time. There have been no instances of the same person being an MP and a local authority mayor at the same time.