all-party 
adjective [attributive] British
Involving all political parties: the measure received all-party support...
- He will win all-party support at Westminster for doing so.
- No sooner was it reported that Labour might endorse such a measure in the election than the possibility of all-party support was being seriously discussed in Westminster.
- It's quite clear from debates in both the Commons and the Lords that there's all-party support for action and that's reflecting the views of the travelling public.