Nightclubs have called on Wales' First Minister Mark Drakeford to give a date when the sector can plan to reopen without restrictions.
An industry body warned ministers could be condemning thousands of businesses to bankruptcy without a date and extra financial help.
One licensee said some operators were "desperate" and running out of cash.
The Welsh government said any decision to relax restrictions must be based on the latest advice.
But it said it would give businesses "as much notice as possible".
Businesses fear that under current plans they have "no hope" of resuming trade except for test events.
In England the UK government has given a tentative date of 21 June at the earliest for when nightclubs may be allowed to reopen. No date has been set in Wales.
Mr Drakeford is expected to reveal his next steps on Covid at a press conference on Friday, following discussions with ministers on Monday.
Coronavirus case rates currently stand at the lowest since last August, with 8.6 cases per 100,000 people over seven days.
Nick Newman, a licensee at Croeso Pubs which owns the Philharmonic and Brewhouse venues in Cardiff, said the situation was bad for nightclub businesses.
The chairman of the Cardiff Licensee Forum said: "There's still a huge sector of our business which has no clarity whatsoever as to when it's going to reopen - nightclubs, venues that specialise in music.
"I know operators of nightclubs who are quite frankly desperate - there's no money left in the bank account.
"The licensees forum compromises roughly 100 businesses - or at least it did before the pandemic started. We've probably lost eight or nine businesses through this. Some of them are smallish businesses - some have been quite iconic."
Pubs and restaurants will be able to reopen indoors from 17 May, with four allowed to meet inside venues. But Mr Newman warned that would have a "crippling effect" on traders' ability to trade profitably.
"The way the night time economy has been treated in Wales during the pandemic just isn't good enough," he added.
Under the current system, coronavirus restrictions are set according to which alert level the Welsh government believes is needed, according to what the risk is deemed to be.
The traffic light control plan has nightclubs and late-night entertainment venues closed at all coronavirus alert levels, except for pilot events at the low risk alert level one.
Mr Drakeford has dubbed Prime Minister Boris Johnson's roadmap for England "very optimistic".
Wales is currently in the high risk alert level three, with plans to move into alert level two if rates remain low on Monday.
An open letter from the Night Time Industries Association (NTIA) asks for "an indicative date for when nightclubs, entertainment-led, and late-night venues will be able to reopen without restrictions".
"Under the alert levels as described in the current 'control plan', these businesses have no hope for reopening other than for test events in the lowest alert level.
"We would stress the importance for our sector of knowing when they will be able to operate without or with minimal restrictions and take deliberate decisions about staffing, debt and investment now, as night time economy businesses in England are currently doing."
It asks for additional financial support: "Welsh government support initiatives to date have been neither sufficient nor comprehensive enough to prevent many businesses in the sector falling into significant debt.
"Without either a clear path to unrestricted opening, or extended and enhanced financial support, the Welsh government is condemning thousands of businesses in our sector.... to bankruptcy," it added.
The letter also calls for consistency for groups that can meet indoors and outdoors - six are currently able to meet outside, and for guidance to be changed so it does not "discriminate" against venues with amplified sound and music.
It is backed by licensee groups in Cardiff and Swansea.
Kate Nicholls, chief executive of UK Hospitality, said only businesses in England could have "some optimism" of reopening soon.
"In Wales, we've only got 17 May as a date to cling on to for indoor hospitality," she told BBC Radio Wales Breakfast.
"We do need that same timeline, that same line of sight that we've got in England and in Scotland, to be able to look at reopening those closed segments of the economy and then looking forward to ending all restrictions altogether."
A Welsh government spokesman said: "We understand the difficulties faced by all businesses, and particularly those involved in the night-time economy.
"We will continue to work with the sector and give businesses as much notice as possible. However, any decision to relax restrictions must be based on the latest medical and scientific advice."
A recent set of pilot events took place in Liverpool, with a music festival, two club nights and a business conference held with no masks or social distancing.
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