European Commission president Ursula von der Leyen has broken her silence over a coronavirus emergency law in Hungary, admitting to concerns that it hands authoritarian leader Viktor Orban sweeping new powers.

Mrs von der Leyen had avoided singling out Hungary until now, in favour of urging all EU member states to respect democracy and the rule of law during the pandemic. Budapest lashed out in response, branding criticism of its law a "witch hunt".

Thirteen EU nations, including heavyweights France and Germany, issued a joint statement on Wednesday that - without explicitly naming Hungary - said they were "deeply concerned about the risk of violations of the principles of rule of law, democracy and fundamental rights arising from the adoption of certain emergency measures". Hungary took advantage of not being named to put its name to the letter on Thursday.

Mrs von der Leyen said on Thursday, “I am concerned that certain measures go too far and I'm particularly concerned with the situation in Hungary."

She warned that if the commission would “take action as necessary as we have already done in the past".

"This is the time to kill coronavirus - not the time to kill democracy," said Vera Jourova, the Czech EU commissioner, who is responsible for upholding EU values and transparency.

Hungary's parliament, dominated by Fidesz, Mr Orban's ruling party, handed the prime minister the power from Tuesday to rule by decree until his government decides the virus crisis is over.

The emergency law also threatens journalists with prison if they publish what it deems "falsehoods" about the virus or the government's actions to slow it.

The law has sparked alarm among rights groups, media organisations and several EU countries, with fears it was a power grab by Mr Orban, who has ruled Hungary for the past decade.

Mr Orban's government argues that it is upholding EU values and press freedom with the emergency law. In Brussels, 11 European centre-Right leaders asked Donald Tusk, the president of the European People’s Party, to expel Mr Orban's party from its ranks.