Trade union federation Cosatu noted with "extreme disgust" that National Treasury spent more than R870 000 on the travels of Malusi Gigaba's wife Norma during the period that he was finance minister.
It called on President Cyril Ramaphosa to put a stop to the "government's addiction to bling".
"This is an insult to workers. This is the same minister who gave us a VAT hike, fuel and [Road Accident Fund levy] hikes, a sugar-sweetened beverages tax and adjusted income tax brackets below inflation," Cosatu parliamentary coordinator Matthew Parks said in a statement on Friday.
This came after Treasury's reply to a written parliamentary question by Democratic Alliance MP David Maynier revealed that the "total cost to the National Treasury of the specified person's (Norma Gigaba's) official travel since 1 April 2017" amounted to what Maynier called "a staggering R873 366.86".
Parks said Gigaba was the same minister who said workers must tighten their belts and moderate their wage increases, and that critical public service vacancies must be frozen.
"Where was this austerity for the minister? What possible value did it have to workers to fly the minister's wife around the world?" asked Parks.
"It may have been legal, but it is disgustingly immoral."
The ministerial handbook allows for ministers' spouses to accompany them on international visits. But this is not good enough for Cosatu.
Government 'addicted to bling'
"It's enough now. Cosatu demands the ANC get its act together. We are tired of government's addiction to bling," said Parks.
"The president must issue an instruction to all ministers, deputy ministers, premiers, MECs, speakers, deputy speakers, mayors and all the others at the feeding trough, that no more wives or husbands will be allowed to travel anywhere at taxpayers' expense. If ministers' wives want to go to Paris, then their rich husbands must pay.
"Equally, we need to review the costs of presidential spouses and dependants and place limits on them."
Parks said Ramaphosa must also ban ministers, deputy ministers, premiers, MECs, speakers, deputy speakers and mayors from buying cars.
"This function must be transferred to Treasury's chief procurement officer and be managed by the government garage. They must determine when cars must be purchased and set modest specifications."
'Tired of being made a laughing stock'
"This is not some reality show. We need government to behave like adults now. We are tired of being made a laughing stock by these politicians and their hangers-on."
Malusi Gigaba was appointed minister of finance during former president Jacob Zuma's dramatic late-night Cabinet reshuffle in March 2017, when former finance minister Pravin Gordhan was removed.
He served in this position until President Cyril Ramaphosa carried out a Cabinet reshuffle of his own.
Despite a court judgment that found Gigaba had lied and acted unconstitutionally Gigaba, unlike other former ministers connected to the Guptas, survived the chop and was moved to the home affairs portfolio.
He had held this portfolio when some members of the Gupta family were controversially naturalised.