The European Union has accused Hungary of spreading "ludicrous conspiracy theories" after it launched a campaign featuring Jean-Claude Juncker and George Soros which claimed they were plotting to endanger national security.

Hungary's campaign features the grinning faces of Mr Juncker and the Hungarian-American philanthropist alongside the slogan "You have the right to know what Brussels is preparing for."

It claims the EU plans to prevent member states from protecting their borders by introducing compulsory refugee quotas and relaxed immigration rules, warning that this would endanger Hungarian citizens.

But on Tuesday afternoon Margaritis Schinas, the European Commission's press spokesman, dismissed the campaign as pure fiction.

“The Hungarian government campaign beggars belief,” he said. “It is shocking that such a ludicrous conspiracy theory has reached the mainstream to the extent it has. There is no conspiracy. Hungarians deserve facts not fiction.”