The U.K. may not be the only one mulling its future in the European Union (EU). In fact, the fierce debates and headline-grabbing warnings surrounding the Brexit vote in June have given hope to euroskeptics around Europe.
Denmark, the Czech Republic and Poland could face their own referendums on EU membership if the U.K. votes to leave, experts believe.
"The main concern is that an unexpected exit of the U.K. from the EU could lead to similar initiatives in other member states, making Brexit the first step towards the disintegration of the union," Antonio Barroso, senior vice-president of political risk consultancy, Teneo Intelligence, said in a report this week.
Recent U.K. surveys put support for a so-called Brexit at around 40 percent.
Angel Gurria, the secretary-general of the Organisation for Economic Cooperation and Development (OECD), warned on Wednesday of the risk of other EU countries following the U.K.'s lead in holding a referendum and voting to leave.
"Brexit … could threaten both the unity of the U.K. (because of the possibility of another Scottish independence referendum) and the unity of the European Union," he said at a talk in London.
More than 100 City of London business people have signed a letter backing a Brexit that was published in the U.K.'s Evening Standard newspaper on Friday.
CNBC takes a look at the other countries that might hold referendums in the wake of a Brexit.
Like the U.K., Denmark has a long history of euroskepticism. The country voted against joining the euro zone in a referendum in 2000 and last December opted to retain its exemption from EU rules on issues like asylum and border control.
Currently, the second-biggest party in Denmark's parliament is the Danish People's Party (DF), which is right-wing, populist and has called for less EU influence on the country.
"Brexit could embolden the increasingly popular DF to push for its own referendum project … the DF may at the very least further limit the pragmatic Venstre party's room for maneuver on EU issues," Barroso said.
The Czech Republic is among the more euroskeptic of the central and eastern European countries that joined the EU in 2004 and 2007. Unlike neighboring Slovakia, which also joined in 2004, it is yet to adopt the euro and appears undecided about doing so.
Euroskeptic parties in the Czech Republic include three nationalist groups and the larger Communist Party of Bohemia and Moravia, which is the third-biggest party in the country's Chamber of Deputies.
"A potential constitutional change may enable several opposition parties (in the Czech Republic) to push for a referendum," Barroso said.
Former Czech President Vaclav Klaus, who negotiated the country's ascension to the EU, has also suggested it now leave the union, according to media reports.
Several other countries in the union have also seen high levels of anti-EU rhetoric, which could only increase in the wake of a Brexit.
Barroso highlighted Austria, Netherlands, Finland, Poland, Hungary and Sweden as at risk.
He singled out Poland and Hungary as two countries where the radical-right, or factions thereof, might call for a referendum on EU membership.
However, referendums are unlikely in the countries that were founding members of the union — including in Germany and France, which are viewed as its lynchpins.
"EU exit could hardly win the backing of a majority of Germans anytime soon — too obvious has been Berlin's influence in Europe," Barroso said.