Taoiseach Leo Varadkar has added his voice to a call for the EU to issue so-called "coronabonds" to help member states fight the economic fallout from the pandemic.

In a letter ahead of a virtual summit of EU leaders tomorrow, Ireland has joined eight other member states in calling for a "common debt instrument" that would "raise funds on the market" to "ensure stable long term financing" to help governments repair the economic damage done by the outbreak.

The common debt instrument, sometimes referred to as coronabonds, "should have sufficient size and long maturity to be fully efficient".

The letter is addressed to the President of the European Council Charles Michel and is co-signed by the French president Emmanuel Macron, as well as the leaders of Spain, Belgium, Greece, Italy, Luxembourg, Portugal and Slovenia.

Absent, however, are the leaders of Germany, the Netherlands, Austria, Denmark and others, the traditional fiscal hawks at EU level.

The letter makes no reference to the idea of using the EU's bailout fund, the European Stability Mechanism (ESM) to provide emergency credit lines to help countries shore up their finances as the economic fallout deepens.

Last night Mario Centeno, the president of the Eurogroup, the body comprising 19 eurozone countries, said there was "broad support" for the idea of the ESM providing low-cost Enhanced Conditions Credit Lines (ECCLs).

Amid indications the idea did not receive unanimous backing, Mr Centeno said more work needed to be done on the idea ahead of tomorrow's videoconference between EU leaders.

The idea of a common debt instrument has won scant support from richer member states like Germany and the Netherlands.

It harks back to the days of the eurozone crisis, when debtor countries wanted the EU to "mutualise" debt through so-called eurobonds.

In an interview with the Financial Times on 22 March, the European Commission economics chief Paolo Gentiloni denied that plans were afoot to start mutualising debt, acknowledging that such ideas provoked concerns in some member states of "moral hazard".

However, he insisted the EU now needed "extraordinary tools" to tackle the crisis.

"We are discussing how to face what [German] chancellor [Angela] Merkel has rightly defined the worst crisis since the war," he told the Financial Times.

"We can't say it is the most serious crisis since the war and then remain with our traditional Italian or German or French or Dutch point of view," he said. "Our tools were designed for a different crisis, and gradually and consensually we should use them, but also introduce new tools adapted to a completely different crisis."

The letter signed by the Taoiseach states: "The case for such a common [debt] instrument is strong, since we are all facing a symmetric external shock, for which no country bears responsibility, but whose negative consequences are endured by all."

The signatories say the funds raised would be used to help member states' healthcare systems respond and to "protect our economies and internal market".

On Monday Germany's economy minister Peter Altmaier rejected the idea of eurobonds.

However, eurozone sources suggest that coronabonds would be different to the ideas being floated at the height of the financial crisis.

"People present this as some sort of eurobonds for corona but it's a different thing," says one eurozone source.

The letter says the common debt instrument could be "issued by a European institution" to raise funds on the market.

It does not specify which institution, but there is speculation it could be the ESM.

"Every time the ESM goes to the market to issue bonds to raise money for this purpose, it gets called coronabond," says the eurozone source. "The idea of coronabonds is going to be used, but I'm not sure people are going to talk about coronabonds in the same way [as eurobonds]."