In an open letter to the Government, leaders from the UK Door Security Association (UKDSA) and Night Time Industries Association (NTIA) pleaded for a relaxation of training requirements.
Rigorous requirements will exacerbate the sector's recruitment struggles, the letter said.
It warned that six-in-10 door supervisor positions were at risk of being unfilled for pubs, nightclubs, bars and festivals.
Fresh training standards require double the hours, taking seven-and-a-half days to complete compared to a previous four day course.
Initial course pass rates have dropped from 90% to under 50% because of tougher standards, the groups said.
What's more, public health requirements will mean that night time economy businesses need 105-110% of pre-Covid security resources, the groups state.
A UKDSA spokesperson said: “We are deeply concerned that a culmination of issues within our sector will generate a dramatic shortfall in licensed security resources.
"It is obvious to everyone that the upcoming season for events and festivals, coupled with the re-opening of hospitality and nightlife, will present an unprecedented level of demand in a very short period of time."
Public health risks
"This is a demand that we won’t be able to fulfill and could put public health at risk," UKDSA spokesperson added.
The organisation called on the Government to act immediately to help businesses, ahead of reopening next month (21 June).
NTIA boss Michael Kill, explained: “The hospitality and night time economy sector has suffered immeasurably in the last 14 months and while we welcome the opportunity to reopen, there is a sleeping giant emerging in the supply chain and workforce resource.
“The culmination of Brexit, regulatory changes and requirement for workers to remain financially buoyant, has left many businesses across different sectors with challenges around retaining their workforce. Late night economy businesses and events will be hardest-hit, as they will be last to advertise for staff.”
The All-Party Parliamentary Group for the Night Time Economy found that 85% of people working in nightlife were considering leaving the sector due to the pandemic.
Nightclubs have been closed since March 2020, the beginning of coronavirus lockdown restrictions in the UK, but are hopeful of reopening next month.
Just 0.03% of participants in the Government's series of large event pilots tested positive for coronavirus, according to initial reports.
Around 58,000 people took part in regulated large-scale events in April and May and were required to take both a PCR test and a lateral flow test before and after attending an event.
Some 15 people reportedly had a positive Covid test in the testing process, according to newspaper reports.
Pub operators have also raised concerns about a chef recruitment crisis, with the number of new hospitality job vacancies rising by 46% in the past two weeks.
Audit, tax and consulting firm RSM looked at the latest UK-wide job postings on recruitment site Indeed and found there were some 39,167 live vacancies for hospitality jobs posted in the last two weeks.
This was an increase of almost half (46%) from 26,736 postings the previous week when indoor licensed trade was allowed to resume in England, Wales and Scotland.
Almost half of the vacancies were listed as chef or cook roles, highlighting the stark impact of Brexit and the pandemic.