Belgium — Member since 1958 Tom Van Grieken Party leader, national chairman, Vlaams Belang, Vlaams Belang Tom Van Grieken is the 30-year-old leader of Belgium's far-right Flemish nationalist party, Vlaams Belang, which advocates splitting Belgium into Dutch and French-speaking nations. Campaigning on an anti-immigrant platform, Van Grieken and his party say they want a Flexit — or Flemish exit — if the E.U. fails to listen to their anti-migration message.

Denmark — Member since 1973 Kristian Thulesen Dahl Leader, Danish People’s Party Congratulating the British in a Facebook post, the Danish People’s Party leader, Kristian Thulesen Dahl, said, “The EU has taken too much power from the states and is now paying the price.” The DPP opposes the E.U., saying, “We will not allow Denmark to surrender its sovereignty,” but it does support alliances with NATO and the United Nations. Many see Denmark as the next potential departure from the E.U. [These countries could be next now that Britain has left the E.U.]

France — Member since 1958 Marine Le Pen President of the National Front; member of the European Parliament, National Front party President of the National Front party of France, Marine Le Pen has urged France to follow Britain’s lead by holding a referendum on the country’s membership in the E.U. On the campaign trail, she tears into immigrants and Muslims. Polls show Le Pen leading the first round of France’s two-stage presidential election this April and May, but losing in the head-to-head second round.

Germany — Member since 1958 Frauke Petry Chairwoman, Alternative for Germany party “The time is ripe for a New Europe,” Frauke Petry of the Alternative for Germany party tweeted. In a response to Brexit, Petry warned the E.U. that more nations will follow the British and “reclaim their sovereignty” if changes are not made. Her party is poised to win big in German parliamentary elections next year.

Hungary — Member since 2004 Viktor Orban Prime minister of Hungary, Fidesz party The far-right, anti-immigrant prime minister of Hungary, Viktor Orban, closed the country to refugees last year, exacerbating the crisis. In Britain, “the decisive issue was the question of immigration,” Orban said in a radio interview. “Europe can only be strong if answers are given to the questions of great significance, like immigration, that strengthen it, not weaken it.” [Trump celebrates Brexit vote: ‘When the pound goes down, more people are coming to Turnberry.’]

Italy — Member since 1958 Beppe Grillo Founder, Five Star Movement party Beppe Grillo, a comedian-turned-politician in Italy who founded the Five Star Movement political party in 2009, has electrified voters fed up with their country’s old-style politicians. A 37-year-old Five Star Movement politician was elected the first female mayor of Rome this year, and another Five Star Movement candidate won the same office in Turin. The party was one of the main opponents of a failed constitutional referendum that led to the resignation of Italian Prime Minister Matteo Renzi. The result emboldened Grillo and his party, which has said that it wants a referendum on leaving the euro. [After Italian Prime Minister Renzi’s defeat, this Trump fan could throw Europe into crisis]