The leader of the Euroskeptic UK Independence Party (UKIP) told CNBC he had a "massive problem" with Romania, potentially adding fuel to accusations that the U.K. protest party is racist.
"I haven't got a problem with Romanians. I have a massive problem with Romania," said Nigel Farage, the head of UKIP, which campaigns for the U.K. to quit the European Union (EU), the political and economic bloc of 28 European countries.
UKIP scored a shock success in the EU's parliamentary elections last weekend, beating the U.K.'s three mainstream parties—the Conservatives, Labour and the Liberal Democrats— to win 27.5 percent of the U.K. vote.
It campaigned on an anti-immigration ticket, highlighting the increase in people migrating to the U.K. from other parts of Europe. This has helped feed accusations of racism, including from the three establishment parties.
On Thursday, Farage told CNBC that "known criminal gangs" from Romania headed to the U.K., where officials were forced to allow them entry because of EU rules governing freedom of movement for people, goods and services.
"Some of these post-communist countries have not made the transition to full western democracy. They have their own minorities, which are discriminated against in a way that is truly shocking when you see it, and organized criminal gangs have got countries like Romania in their grip," Farage said.
"We, as members of the EU, cannot stop known criminal gangs at the border."
Following the weekend's success, Farage predicted UKIP would win a "good number" of seats in the U.K.'s national elections next year. Then it would petition for a referendum on EU membership—already promised by the Conservative party if it wins—which Farage forecast would be won by the "no" vote.
"If we can keep that momentum going, and bring this to a referendum, and give the British people a chance to decide: should we govern ourselves, in our own country in our own parliament, or should we be governed by the bureaucrats in Brussels, I think if we can get it to that point, (the 'no' vote) will win," Farage told CNBC.
"And when we do that, we don't just get back our independence, democracy and freedom, the rest of Europe will follow us too."
Euroskeptic populist parties in other countries also scored victories in the European Parliament elections. These included the French far-right National Front, which won the elections in France. Extreme-right parties did well in Denmark and Hungary too.