A total of 12 trade associations and 429 individual businesses from the country's hospitality, tourism and events sector have written to the Taoiseach expressing their major concerns about the current response to Covid-19.
The letter is co-signed by 216 hotels, 115 pubs and bars, 52 companies from the event sector or that supply the drinks and hospitality sector.
It is also signed by 19 alcoholic drinks suppliers, 27 food and non-drinks suppliers and 12 trade associations on behalf of their entire membership.
Businesses on the letter include the Bord Gáis Energy Theatre, Dalata Hotel Group, Daa, Diageo, Irish Distillers, The Chawke Group, Coca-Cola and Ballymaloe House.
The letter states that the Government's response is centred on restricting economic activity to a much greater extent than any other country in Europe.
This includes full or partial closures of non-food pubs, and much harsher international travel restrictions than the country's European neighbours.
Today's letter says that many businesses operating in the experience economy are being constrained disproportionately.
It says the current Irish approach risks not just short term, but long-lasting and irreparable damage to the economy and Irish society.
The letter also points out that the experience sector contributes €4.5 billion in wages, salaries and employment taxes every year. More than 330,000 people are either employed directly or supported directly by demand from the sector.
It urges the Government to look to best practice internationally and to countries that have managed to keep their experience economy sector open while at the same time taking clear and targeted approaches to controlling the spread of the disease in communities.
It also calls for a much more targeted set of measures and supports for the sectors most impacted by Covid-19.
Meanwhile, Chartered Accountants Ireland (CAI) has written to the Minister for Finance and Minister for Public Expenditure and Reform emphasising the "colossal disruption" to Irish business that would be caused by the implementation by NPHET to move to Level 5.
"It is clear to us that if a change in restrictions to Level 5 is to be introduced, many businesses particularly those in the SME sector will suffer greatly, and many lower paid jobs in particular will be put under threat," CAI said.
"This is based on the experience of our 19,000 members employed in industry and practice in this country."
It said if the additional restrictions are imposed, the Temporary Wage Subsidy Scheme (TWSS) should be reinstated to April levels, at a cost of around €700m.
This is needed, it claimed, because delivery of the TWSS is immediate and therefore better than the Employee Wage Subsidy Scheme currently in process.
The CAI also said Revenue should immediately warehouse all fiduciary tax obligations for the duration of Level 5 at an expected cost of €800m for the month of October.
It also wants the suspension of reporting and filing obligations to the various agencies governed under the ministers' remit and by the Department of Business, Enterprise and Innovation.
The association also proposed the introduction of a premises maintenance grant to prevent the deterioration of partly or fully closed premises during inclement winter weather.
"We recommend that an immediate grant of the 15% of the rates payable annually on each premises be provided to assist in ensuring that, when the restrictions ease, businesses can reopen as quickly as possible," it said.
"By reference to the cost of the rates forbearance measures earlier this year, such a grant will cost in the order of €150m."
