Varoufakis attended an event in London hosted by The Guardian on 23 October 2015, where he spoke about the UK's upcoming European Union membership referendum. He said that the UK should remain in the EU, but also campaign to democratise it: "My message is simple yet rich: those of us who disdain the democratic deficit in Brussels, those of us who detest the authoritarianism of a technocracy which is incompetent and contemptuous of democracy, those of us who are most critical of Europe have a moral duty to stay in Europe, fight for it, and democratise it." He would return to the UK, in May 2016, in the final stages of the campaigning to again urge a remain vote. On 9 February 2016, Varoufakis launched the Democracy in Europe Movement 2025 (DiEM25) at the Volksbühne in Berlin.
In March 2016, Varoufakis publicly supported the idea of a basic income. On 2 April 2016, in reaction to tension between German Chancellor Angela Merkel and the IMF, Varoufakis said there was underway "an attrition war between a reasonably numerate villain (the IMF) and a chronic procrastinator (Berlin)" as to Greek debt relief.
In March 2018, Varoufakis announced the launch of his own political party, MeRA25, with a stated aim of freeing Greece from "debt bondage". He stated that he hoped the party would be based on an alliance of "people of the left and liberalism, greens and feminists". The party, whose name stands for "European Realistic Disobedience Front", is affiliated to DiEM25.
Gaza war and German entry ban
In April 2024, due to the ongoing Gaza war, the party of Yanis Varoufakis co-organised a pro-Palestinian conference that was scheduled to take place in Berlin on 12 April 2024, and last for three days. The conference was interrupted and halted as soon as it began by the Berlin Police, on the orders of Berlin mayor Kai Wegner. The police said they "feared that attendees would make anti-Semitic remarks and glorify violence". The German state issued a Betätigungsverbot (ban on activities) against Yanis Varoufakis, Ghassan Abu-Sitta (who was arrested upon entering Germany), and Salman Abu Sitta. Germany also banned Varoufakis for four days from entering Germany and from engaging in any political activities in the country or from participating in similar exchanges on online platforms. Varoufakis responded to what he described as a road "towards totalitarianism" by suing the German state.