Taoiseach Leo Varadkar believes the formation of a new government, particularly one that includes Sinn Féin, could impede the current efforts to deal with the coronavirus crisis.

In a new attack on Sinn Féin last night, a government spokesman said the reasons why Mary Lou McDonald's party should not participate "are even more valid in an emergency" and said a new administration "would not make it any easier" to deal with the outbreak.

"The reasons why Sinn Féin should not participate in government are even more valid in an emergency, particularly when it comes to national security, the Garda, the Defence Forces and the justice system," the spokesman said.

He said the caretaker government was devoting its efforts to the unfolding situation and the opposition was being briefed regularly.

A Cabinet sub-committee meets today to consider further measures, including expediting sick pay for those forced to self-isolate.

The spokesman added: "Covid-19 will be with us for many months and should not prevent a new government from taking office at the appropriate time. However, the appointment of a new government would not make it any easier to deal with Covid-19 in the short term.

"It would mean more than a hundred people taking up new roles across government, many of whom would have no prior experience of government or their new role, and would have to devote time to read into their new brief."

Sinn Féin did not respond to a request for comment.

Some Fianna Fáil TDs have backed calls for a national government involving all parties, including Sinn Féin, to tackle the coronavirus crisis. However, senior figures in Fine Gael and Fianna Fáil have ruled it out.

Mr Varadkar spoke with Ms McDonald yesterday after she called for a meeting of all party leaders to discuss the crisis. The Taoiseach's spokesman said Mr Varadkar would consider a meeting.

The pair did not discuss government formation with Mr Varadkar maintaining his view that Fine Gael should go into opposition. However, three senior Fine Gael ministers have signalled their willingness to go back into government. Justice Minister Charlie Flanagan has called for a FF-FG-Green government and "a new deal for Ireland".

Tánaiste Simon Coveney believes a "strong and stable" government will be in place this year, his spokesman said. Writing in the 'Sunday Independent', Finance Minister Paschal Donohoe said the election result represented the "last opportunity to salvage" the political centre.

Meanwhile, Fine Gael TDs have criticised health authorities' refusal to disclose counties where outbreaks are happening. Clare TD Joe Carey said it was "ridiculous", while Cork North-Central TD Colm Burke supported disclosing specific counties. Senior health officials have ruled revealing more details.

Irish Independent