Measures announced on Wednesday (8 December) include the reintroduction of homeworking, mandatory face coverings extended to other indoor venues and covid pass or negative lateral flow tests needed for big venues.
TSSA represents frontline travel agents and industry workers across the UK and Ireland.
General secretary Manuel Cortes said the government has "failed to act quickly enough" or "take the measures needed" to prevent the spread of Covid throughout the pandemic.
"Our members in the travel industry are already suffering as a result of the reintroduction of travel restrictions and now many more workers are going to feel the pinch as Plan B kicks in," he added.
"The government must bring back the furlough job retention scheme to ensure no one loses their jobs as a result of the new restrictions."
Cortes said "serious measures" need to be taken to "save lives and protect public health".
"The government must bring back the furlough job retention scheme so that businesses and workers can fully comply with Covid measures without the fear of job losses or businesses going bust."