Hospitality Ulster chief executive Colin Neill has warned of "mass redundancies" unless Stormont brings forward the reopening of pubs, restaurants, hotels and cafes to the end of this month.
He was speaking as the heads of four local Chambers of Commerce called on the Executive to fast-track the opening of businesses here in line with plans announced by the Irish Government on Friday.
The leaders of Newry, Belfast, Causeway and Londonderry chambers say that not doing so means retailers and hospitality businesses here, particularly those in border areas, will be left "at a competitive disadvantage".
They said: "At a time when many businesses are struggling we can't afford to lose more business to the south through unfair competition.
"Our members have invested significantly in measures to protect the safety of their staff and customers and are ready to open."
The business leaders say the time is right for the Executive to accelerate the opening of retail and hospitality sectors and allow them to trade on an equal basis with others on the island.
"Retailers are at the very heart of their towns and cities, employing local people and would not put their communities at risk," they added.
"With the right safety measures in place, now is the time for retail to open again and give our high streets an opportunity to recover.
"Equally, our hotel and hospitality sector needs the opportunity to open earlier.
"July is the peak season and if the southern hospitality sector is allowed to trade from June 29, our hotels, restaurants, pubs and B&Bs will suffer further losses.
"Many families will have to stay at home for their holidays this summer and our hospitality sector needs the opportunity to compete for this 'staycation' business."
DUP Economy Minister Diane Dodds will today urge her ministerial colleagues to consider reducing social distancing guidelines here from two metres to one metre so businesses can serve more customers.
The World Health Organisation (WHO) recommends one-metre social distancing, but the UK and Republic believe two metres is the safest option.
Mrs Dodds told the Belfast Telegraph on Saturday that she wanted to see "as much of our economy open as possible" and that the economic consequences of not opening for business would be colossal.
The Executive will discuss the DUP proposal when it meets this morning.
Taoiseach Leo Varadkar has announced a fast-tracking of the Republic's journey out of lockdown, with all shops allowed to reopen from today unless they are in a shopping centre and provided social distancing regulations are observed.
Bars in the Republic serving food can also open their doors again from June 29.
Ahead of today's Executive meeting Mr Neill, CEO of trade body Hospitality Ulster, backed the chambers' joint call and said businesses were simply unsustainable under the current two-metre social distancing guidance.
"The hospitality industry has extensive health and safety plans in place and the health of our staff and customers will remain our priority," he said.
"With the Government's staff furlough scheme requiring businesses to contribute at the end of July, our hospitality businesses have been closed since March 20 and have no money.
"Unless the NI Assembly bring forward our reopening or pay the employer contributions, we will see mass redundancies.
"With a four/five-week supply chain we need a reopening date now."
His views were echoed by Retail NI chief executive Glyn Roberts.
He said: "With the Irish Government setting out a roadmap for its retail sector to reopen, the Executive must now also set a date, otherwise many local towns and retailers along the border will be at a major competitive disadvantage.
"We need a date and we need it now, as retail plays a key role not just on our high streets, but our economy as a whole."
Mr Roberts added: "Moving from two metres to one-metre social distancing is crucial for retail and hospitality as they reopen, and we urge the Executive to look at how this can be done in a safe way."