I think
Smokeandsteam has outlined some "credible" (and of course that do you mean by this) outcomes over the last couple of pages. But one obvious credible outcome would be re-nationalisation of industries, at this very moment RMT members are on strike in order to ensure their jobs are safe because train companies want to remove guards. The EU is part of the attack on their jobs and leaving the EU can provide their job security.
Capital and labour are in constant antagonism, labour develops new ways of asserting its power only to see those structures co-opted by capital. The trade unions themselves are an excellent example of such. But as stated some
pages back either you believe in the power of the working class to improve things or you might as well reject socialism entirely.