Giving evidence to the House of Commons Treasury Committee, Nicholls highlighted the damaging effect the restrictions were having on a sector which is already on the brink.
Declining revenues since the introduction of the curfew have already led to business closures, with the increased potential for further failures.
Staff shifts have had to be removed to accommodate the early closing time, putting workers at further risk of job losses.
The lack of a staggered closing time in England and Scotland has also created a potentially dangerous pinch point as customers are forced to leave venues en masse.
UKHospitality has called for a complete rethink of the curfew and repeated calls for a comprehensive package of support to safeguard businesses and jobs.
Speaking after the session, Nicholls said: “The introduction of the curfew has had a severe and devastating impact.
“Businesses are feeling the cumulative impact of all the restrictions placed on them, but they have really suffered since the introduction of the curfew. The curfew has wiped away revenue from businesses that were only just clinging on. For many, it has tipped them into financial unviability.
“We have no staggered ending like we have seen in Ireland and Wales. Other European countries have a later curfew point, with last orders at 11 and closure at 12, which eases the pressure.
“The Regulatory impact on businesses needs to be considered, particularly when so low a number of outbreaks are linked to hospitality. We urge the Government to rethink the curfew so that it can deliver the public health objective without damaging businesses and risking further job losses. We also need an immediate and comprehensive package of support to keep businesses alive and prevent redundancies on a large scale.”