Hungarian Prime Minister Viktor Orban has said he has "no time" for scathing criticism from fellow European Union members of the sweeping powers he took this week to tackle the coronavirus threat.

Thirteen European centre-right parties urged their European People's Party political group to expel Mr Orban's Fidesz party after he assumed emergency powers on Monday.

Mr Orban insists he must rule by decree to tackle the spread of the pandemic. But many, including some of his allies in the EPP, accuse him of a power grab gone too far.

"With all due respect I have no time for this," said Mr Orban in a letter to EPP Secretary General Antonio Lopez-Isturiz White posted on Twitter by one of his ministers, Katalin Novak.

"I can hardly imagine any of us having time for fantasies about the intentions of other countries. This seems to me to be a costly luxury these days," he wrote.

"I am ready to discuss this once the pandemic is over," he added.

The Scandinavian, Greek, Belgian, Lithuanian, Czech and Slovak conservatives, who signed the statement calling for Fidesz to be kicked out of the EPP, do not represent a majority of the group.

But their letter strengthens the hand of party chairman Donald Tusk, the former Polish leader and president of the European Council, who is pushing the EPP to distance itself from Mr Orban.

The signatories call on the EU executive, the European Commission, to "address the situation in Hungary forcefully" and brand Mr Orban's move a "violation of the founding principles of liberal democracy and European values".

Under the emergency law, Mr Orban has the power to rule by decree until his government decides the virus crisis is over.

It also threatens journalists with prison if they publish "falsehoods" about the virus or the government's actions to slow it.