The next Mayor of London and London Assembly elections are on Thursday 4 May 2028

Campaign spending and expenses

Candidates are limited in how much they can spend on their election campaigns during what is known as 'the regulated period'. The limits apply to spending on activities in the following categories:

  • advertising
  • unsolicited material sent to voters
  • transport costs
  • public meetings
  • staff costs
  • accommodation costs
  • overheads and administration

In 2024, the limits on expenditure for the London elections were:

Mayoral candidates: £760,410
Constituency London Assembly Member candidates: £63,360
London-wide Assembly Member candidates: £597,460 (for an individual independent candidate or political party list)

The expenditure limits for 2028 will be confirmed by the UK government in due course.

The regulated period for Mayoral candidates, Constituency London Assembly Member candidates and independent London-wide Assembly Member candidates begins on the day after the date an individual officially becomes a candidate. For London-wide Assembly Member candidates on a political party list, the regulated period begins on the day after the date the political party list is submitted to the Greater London Returning Officer.

Candidates have to declare their expenditure to the Greater London Returning Officer (Mayoral and London-wide Assembly Member candidates) or the Constituency Returning Officer (Constituency London Assembly Member candidates) after the results have been declared. All expenditure has to be declared within 70 days for Mayoral and London-wide Assembly Member candidates and 35 days for Constituency Assembly Member candidates.

There are rules governing donations and loans which can be accepted either as a political party or a regulated donor (individual or group).

More information about the rules on spending, donations, and the reporting requirements after elections are available in the Electoral Commission’s guidance on spending and donations. Queries about the rules for candidates and political party spending and donations should be directed to the Party and Election Finance team at the Electoral Commission.