Consumers confidence has recorded its biggest monthly fall since it was first surveyed 24 years ago, while spending is set to plummet by €2.6bn a month compared to last year.
Experts said the April reading suggested a sea-change in Irish consumers' thinking about their economic circumstances in response to the coronavirus.
The 35-point fall in sentiment was larger than that recorded in the US, according to KBC Bank.
And consumer spending using credit and debit cards, as well as cash withdrawals, are set to plunge by an estimated €2.6bn, or 40pc, this month from a year ago, according to the Central Bank of Ireland.
Research from the Central Bank published today tracked spending and cash withdrawals as the lockdown progressed.
It said the value of both card spending and ATM withdrawals declined rapidly from March 16, in part due to the St Patrick's Day bank holiday.
By the time the stay-at-home order was announced on March 27, the value of card spending had already declined by more than a fifth since the first week of March, while the value of ATM withdrawals was down more than 40pc.
"This pattern of declining spending and cash withdrawals has continued into the first week of April, with card spending down by almost a third and ATM withdrawal amounts down 57pc on the first week of March," economists Andrew Hopkins and Martina Sherman wrote in the report.
"If the current level of spending and ATM withdrawals were to continue for the remainder of April 2020, it is estimated that overall card spending and cash withdrawals would be €2.6bn (40pc) lower than in comparison with April 2019," the report said.
Even though cash withdrawals have been hit hard, the data shows the average ATM withdrawal amount has increased markedly from €137 during the first week of March to around €178 by the first week of April.
With more than half a million workers now reliant on the Government for incomes and businesses shuttered across the State, the economic toll of the pandemic is rising sharply and the International Monetary Fund (IMF) said yesterday that the world was set for its biggest economic crash since the 1930s.
The Central Bank of Ireland is forecasting that the economy will shrink by more than 8pc this year.
The KBC Bank Consumer Sentiment Index fell to 42.6 in April from 77.3 in March.
KBC Bank economist Austin Hughes said the monthly confidence drop was the largest in survey's 24-year history.
He said the April reading was still marginally above the low point of the index - 39.6 recorded in July 2008 - but the decrease this time has been more sudden.
It was one of the weakest assessments of consumer conditions on record, he said.
Mr Hughes said the scale of the fall in sentiment was so great it was something that might be expected to happen only every couple of hundred years.
"As such, the April reading suggests a sea-change in Irish consumers' thinking about their economic circumstances in response to the coronavirus," he said.
He said it was likely the fall in sentiment had been much sharper here than in the US as households in this country were still "scarred" from the financial crisis more than a decade ago.
Mr Hughes said any suggestion of new austerity measures would halt consumer spending even more.
The IMF predicted this week that Ireland will record the second-biggest rise in unemployment in the euro area this year.
Almost of a third of the workforce is now claiming unemployment benefit from the State. There are 743,000 people who are currently on either the special Covid-19 emergency jobless benefit or the standard dole.