Conversation so far:
what were ken's affiliations before 2005?
Loach supported the Trade Unionist and Socialist Coalition in the London Assembly election, 2012.
how did his support turn out?
With the support of the activist Kate Hudson and academic Gilbert Achcar, Loach launched a campaign in March 2013.
how did the campaign turn out?
launched a campaign in March 2013 for a new left-wing party which was founded as "Left Unity" on 30 November.

Question: what was his absolute biggest accomplishment?
Self-contained rewrite: what was Ken Loach's absolute biggest accomplishment?