Shopping centres in the Venezuelan capital, Caracas, say they will be halving their opening times to four hours a day.
The move will allow them to comply with government energy rationing.
Ministers says a severe drought caused by El Nino has brought 18 of the country's hydro-electric dams to critically low water levels.
A spokesman for the country's retail association said the drop in working hours would have an impact on jobs.
The state energy corporation (Corpoelec) had wanted cuts twice a day, between 1pm and 3pm and then again between 7pm and 9pm.
The retail association, The Chamber of Venezuelan Commercial Centres (Cavececo), said it had made an alternative proposal: that shops should open late at 12:00 and close at 19:00 saving five hours of energy use daily.
But they had not received a response to this suggestion, the organisation said.
"To turn the lights off at one in the afternoon and not to be able to work would have a huge impact on our business," said Mleidys Galves who works in a pizzeria in the Lider Shopping Centre in Caracas.
"That is our peak selling time when people come out to eat lunch."
Cavececo said opening and closing twice in a day would be disastrous for banking operations, health centres, servicing companies, pharmacies, supermarkets and particularly restaurants that depended on electrical energy to preserve and refrigerate their products.
However, the reduction to only four hours a day would also have an impact on businesses that ran two work shifts which represents around 75% of employees in shopping centres.
The government has also asked private residences to start saving energy and has been rationing domestic water supplies since January.