DISAFFECTED voters could hasten the demise of the European Union today as Italians vote in a referendum on constitutional change and Austrians go to the polls to elect a new president, with strong indications that voters in both countries are ready to support populist alternatives to traditional parties, such as with Brexit and Donald Trump’s US presidential victory.

Matteo Renzi, Italy’s prime minister, has pledged to resign if voters reject his bold plan to limit the power and size of the Senate, the upper house of parliament, and transfer most of the legislative clout to the Chamber of Deputies, the lower house. His reforms would increase central government power over regional authorities, and give the national ruling party almost total discretion to devise and introduce legislation.

Over the past few months Renzi has been trying to rally support around the country. Polls have suggested he is up to five points behind the populist, anti-establishment and eurosceptic Five Star Movement, led by comedian Beppe Grillo.

Renzi’s message to an audience in Treviso was typical of his entire campaign: “If you want this country to change – not for me, not for you, but for the sake of our children – if you want it to have a simpler system, stand by me, because I can’t make it alone. The world needs Italy. I don’t want a country that is a museum but one that is a laboratory. One we can be proud of.”

There can be no disputing that Italy needs change. Its income and gross domestic product (GDP) are both lower than they were 10 years ago; its level of public debt is second only to that of Greece; and it has one of Europe’s worst youth unemployment rates. Renzi and his Yes camp hope the changes they are proposing will make the government more efficient, allowing them to address these pressing problems.

A Yes vote would be a major coup for Renzi, but a No victory could end his political career and herald a seismic shift in Italy’s political landscape. The Five Star Movement is becoming increasingly popular, winning a quarter of the votes in the 2013 election and two major mayoral races this year, in Turin and Rome. Were the Italian referendum result to echo the Brexit vote and Trump’s victory, Grillo’s party could sweep in and potentially lead to Italy exiting the eurozone, or the EU – in what has been dubbed “Quitaly”.

Grillo has also compared his party’s rise to Trump’s success, saying: “We’ll win the general election, and they’ll continue to wonder, ‘how do they do it’?”

The No camp, epitomised by Five Star, appears to have broad support with four former Italian prime ministers – including Massimo D’Alema, on the left, centrist Mario Monti and right-wing Silvio Berlusconi – all coming out against the proposed changes.

Voters in Austria, meanwhile, are faced with a left-wing Green candidate or a far-right xenophobe as they go to the polls today to elect their president. Most polls put the Green Party’s Alexander Van der Bellen behind his Freedom Party (FPO) rival Norbert Hofer, for whom victory would signal another blow for the EU. This ballot is a re-run of the presidential poll held in May, when Van der Bellen beat Hofer by just 31,000 votes. Procedural irregularities allowed the FPO to get that result overturned.

Hofer disputes the general view of his party as “far-right”, despite its anti-immigration stance, but like Grillo in Italy, he says he has been encouraged by Trump’s success in the US. Although the presidential post is largely ceremonial, he has said he will push for a referendum on Austria’s EU membership if Turkey joins the bloc, or if it becomes too centralised.

Debates between the two candidates have been ill-tempered affairs, with Austria’s Nazi past featuring frequently, and images of Adolf Hitler being used to slur both men.

One Holocaust survivor, known as Gertrude, has urged young Austrians to think carefully about who they vote for to stop history repeating itself.

Gertrude, now 89, was just 16 when she and her family were deported to Auschwitz. Her parents and two younger brothers perished in the camp and in a video which has gone viral, she warns: “People cannot always complain, and then when there is an election choose not to vote. For me it is probably my last elections, but young people still have their whole life in front of them.

“Hate was instilled or actively brought forth in people [by the Nazis]... degrading and laughing at others. Like the Jews - they had to clean the streets. The Viennese - men, women and children - they stood by and laughed at that. And exactly that [attitude] one is trying to re-invoke in people today. And that hurts; that is what I fear.”