Analysts at Citi have called a probable Italian referendum on constitutional reform next fall “the single biggest risk on the European political landscape this year,” bigger even than Brexit.

In the midst of much hand-wringing over the possible consequences of the recent UK decision to detach itself from the European Union, Citi is saying that more serious dangers loom large on the horizon; namely upcoming referendums in Hungary and Italy.

In a memo titled “Global Economics View: Who’s Next? EU Political Risks After the Brexit Vote,” Tina Fordham, Citi’s chief global political analyst, informed clients that Italy’s referendum poses a higher risk for EU stability than the Brexit vote.

“Hungary (on EU refugee quotas) and Italy (on constitutional reform) will likely have referendums in H2 2016. The latter is probably the single biggest risk on the European political landscape this year among non-UK issues, as PM [Matteo] Renzi’s political future may be tied to the outcome of the referendum,” the memo reads.

Citi said that despite rising Euroscepticism across many countries, it does not expect any other In/Out referendums in an EU country in the near-term. In most EU countries electorates do not have the power to directly trigger EU referendums and those with the power to do so (usually Parliaments) “appear unlikely to use it,” Citi said, although “in an environment of diminishing trust in elites, the temptation to seek political legitimacy through referendums is tempting.”

Italy’s upcoming referendum will deal with major Senate reforms which, if approved, could improve the stability of Italy’s political machine and give Renzi some breathing room.

If the referendum fails, Renzi’s government will fall, and Italy will return to the sort of political anarchy that followed the ousting of former Prime Minister Silvio Berlusconi.

Analysts suggest that with Eurosceptics holding momentum, the reforms may very well fail. In recent mayoral elections throughout the country, Renzi’s Democratic Party (PD) took a beating, while the populist, Eurosceptic Five Star Movement (M5S) won 19 of the 20 cities in which it had a candidate in the running—including Rome and Turin.

There is a growing movement across Europe to allow citizens to decide whether or not to stay in the beleaguered EU, and analysts suggest that after Brexit other countries across Europe will likely hold their own referendums.

As Breitbart News has reported, mounting populist sentiment is allying with traditionally Eurosceptic parties across the continent and groups in France, Slovakia, the Netherlands, Denmark, and Sweden are asking for their own referendums in what is being called Europe’s “Patriot Spring.”

Follow Thomas D. Williams on Twitter Follow @tdwilliamsrome