Two out of every five businesses in the tourism sector have failed to reopen since the lockdown in March, with only one in eight operating at full capacity.
The results of a new survey by Fáilte Ireland show only 61pc of firms reopened for business at some stage in the past six months.
In addition, only 13pc are operating to the maximum level, with more than half of all tourism businesses claiming they were operating below 50pc capacity.
The survey of more than 950 firms in the tourism sector conducted last month also revealed that 13pc of businesses said they had ceased trading as a result of the restrictive measures.
Fáilte Ireland said the findings mostly apply to 2020 and did not necessarily mean the businesses had closed permanently.
Thirty-one per cent of businesses said their bookings were down by more than half this year.
"Generally speaking, those reopening are less dependent on large groups and overseas tourists and are more likely to capitalise on the domestic market," a Fáilte Ireland spokesperson said.
B&B owners have been worst affected by the Covid-19 pandemic, with only 45pc having reopened since March.
The figure was 63pc for pubs and 68pc for hotels, while 71pc of tourist attractions had reopened.
The highest level of reopening was among restaurants, with 76pc were trading over the summer.
Fáilte Ireland said the sector in Dublin had been hit particularly hard, with 98pc of tourism businesses in the capital reporting reduced customer levels, due largely to the city's reliance on the overseas tourist market.
It claimed the restrictions on the staging of events such as festivals, exhibitions and sports meant Dublin's tourist offering was not currently appealing to domestic tourists.
As for the traditionally quiet- er autumn period, 90pc of businesses said they had fewer bookings than normal from tourists.
In terms of government supp-orts, the Employment Wage Subsidy Scheme was the most valued, with 42pc of businesses claiming it would be their choice if they could avail of only one initiative.
A reduction in VAT was cited as the next most welcome support, favoured by 16pc of businesses.
The survey showed 44pc of all businesses in the sector had sought finance to get them through the crisis, of which almost two-thirds said they were successful in securing funding.