The UK's public finances are not in great shape, with estimates of tens of billions of pounds needed to be found in tax increases or spending cuts in the October budget. (And the recent U-turn on disability benefit cuts removes one potential avenue for spending cuts.)

Reluctant to break their manifesto pledge of not increasing income tax, will the government introduce a wealth tax?

If a wealth tax is introduced by the end of 2025 (realistically in the October budget), market resolves YES. The tax doesn't need to actually be in place (I assume that will start with the next financial year) but does need to be passed by Parliament.

I expect that the definition of a "wealth tax" will be straightforward. Considerations will be: does the government call it a wealth tax? Do mainstream media sources call it a wealth tax? In my judgement, does the policy result in wealth being taxed?

In the unlikely event that judgement is required, I won't bet in this market. If you think any of my resolution criteria are unclear or should be refined, please let me know. For two weeks from market creation date, I might tweak the resolution criteria, so you might want to not place any very large bets in that period, especially if you intend to win on a technicality. The spirit of the market will not change.

• Update 2025-07-08 (PST) (AI summary of creator comment): Following a user question, the creator has clarified that the introduction of an unrealised capital gains tax would be sufficient to resolve this market to YES.

• Update 2025-07-08 (PST) (AI summary of creator comment): The creator has clarified that the following will not be sufficient to resolve this market to YES:

  • The introduction of a land tax

  • Changes to property taxes, such as a major increase or re-evaluation of council tax bands

• Update 2025-07-10 (PST) (AI summary of creator comment): In response to a question about a tax limited to certain assets (e.g., a high-value real estate wealth tax), the creator has stated they are leaning towards this being sufficient to resolve YES.

This is because such a tax, while on property, is commonly called a 'wealth tax' and targets high values, distinguishing it from a general property tax which has been ruled out.