Trade unions in the UK are very influential in the political sphere when it comes to the formation of policy. Almost every employment law in place in the UK today started life as a trade union policy and bubbled up into UK or EU law.
Given the current leadership challenge in the affiliated party – Labour – that got triggered today, this might well become a major debated policy.
The unions support the incumbent leader (Jeremy Corbyn), who is likely to be receptive of Basic Income as a policy. Angela Eagle (the challenger) is more to the right of the party (but still very left compared to say, US politics), and is likely to be less keen. That said, it’s a possibility.
All in all I think this is a very positive step for it becoming part of the political mainstream and into the national debate.