Only three months remain before Britain votes on whether to remain in the European Union, and the exit campaign is gaining support as politicians capitalize on the Brussels terror attacks to argue for a "Brexit."

A poll released by ICM Wednesday shows support for a British exit is at 43 percent, the highest level since tracking began in May 2015, Reuters reported. The poll surveyed 2,000 people over the weekend before Tuesday’s terror attacks in Brussels that left at least 34 people dead and at least 230 wounded.

Politicians campaigning for a Brexit linked Tuesday’s attacks to the failings of the EU, arguing that Britain would be safer outside of the 28-state union. Nigel Farage, leader of the U.K. Independence Party, said Wednesday he was “wholly justified” in linking the Brussels attacks with EU immigration laws, the BBC reported. He described Brussels, one of the EU’s key cities, as the “jihadi capital of Europe.”

“What is shameless is putting lives at risk for the sake of political union,” said Mike Hookem, UKIP's defense spokesman. “[Prime Minister David] Cameron says we’re safer in the EU. Well, I’m in the center of the EU, and it doesn’t feel very safe.”

Hookem went on to argue the attacks in Brussels show that the EU’s free movement Schengen border system is broken and threatens security, Politico EU reported. Cameron argued it was not “appropriate” to use the events in Brussels as part of a political campaign. Four British citizens were wounded in the attacks in Brussels.

Cameron’s government has been dealing with a revolt in its own Conservative Party, with Works and Pensions Secretary Iain Duncan Smith resigning last week. Smith, who supports a British exit, said his resignation who not tied to debates over the EU.

Britain will hold a referendum on quitting the EU on June 23. Cameron has been leading the effort for the U.K. to stay, while Farage and rebel Conservatives are supporting the Brexit side.