That depends I guess. Surely that won't be a mass party and as a catch it all party it's not suitable either. But an intelligent approach would be to force Labour & Tories to compete outside metropolitan areas while hovering up urban constituencies. /1
If they manage to campaign there effectively, ally w/ SNP, moderate Irish parties and Plaid Cymru, they could gain a significant number of MPs. They'd need to adjust their campaigns outside urban areas to make sure that neither Tories nor Labour can get an overall majority. /2
They could, e.g. call their voters to vote tactically to pursue a hung parliament. In that moment they could for force either Labour or Tory to devour each other by forcing them to work with each other or divide and rule. In any case, I'd not say that such a project's doomed. 3/3
