In an exciting new collaboration, WISERD’s UnionMaps data has been integrated into Strike Map, a worker-powered and funded map of industrial action, which has mapped 230,000 strikes since 2020. The combined functionality of both platforms will allow users to see union strength in the areas where industrial action is happening.
Rhys Davies, WISERD co-director and senior research fellow at Cardiff University said: “Data from UnionMaps reveals the complex patterns and trends in union membership that exist across Great Britain. We are very pleased that this data has been integrated into Strike Map to support the work of volunteers and trade union activists who will now have access to detailed statistics about the strength of the union movement in areas where industrial action is taking place to inform their work.”
As shown in the screenshot below, UnionMaps data will now show, for every strike, local authority level information on union power and strength, including:
- Union presence — the percentage of employees who are a trade union member or who are employed at a workplace where others are members.
- Union membership — the percentage of employees who are a trade union member.
- Union coverage — the percentage of employees who report that pay and conditions are agreed in negotiations between their employer and a trade union.
- Collective agreement — the percentage of employees whose pay is set with reference to an agreement affecting more than one employee.
Strike Map co-founder, Henry Fowler, said: “We are committed to improving our map and its use for activists to win their disputes, campaigns and re-balance power in our country. UnionMaps provides key data on the collective strength of our movement for detailed geographical areas, including union membership and the coverage of collective agreements. We are delighted to be able to add this new data to our map so that hundreds of thousands of our supporters can understand the strength and power of their local trade union movement in areas where strikes are taking place.”
Visit Strike Map to find your local strike and see the UnionMaps integration.
Image credit: Henry Fowler, Strike Map, taken 20 September 2025 at Birmingham Bin Strike demonstration