Japanese car companies will stop working on Thursdays and Fridays next month and transfer shifts to weekends in a move that industry executives hope will relieve the pressure on Japan's faltering electricity supply.

The move comes as the UK outposts of major manufacturers, which between them employ more than 10,000 workers, target a return to 100% production following disruption due to component shortages from earthquake-hit Japan. Nissan said it had "stabilised" the situation at its Sunderland plant, while Toyota has promised to claw back UK production losses by the end of the year.

Honda has cut its production target at Swindon from 122,000 vehicles in 2011 to about 102,000 and will not return to pre-tsunami production levels until after its summer break. "It has been tough and it will present a challenge for the back end of the year," said a Honda spokesman.

Japan's key role in the UK car industry was underlined by production figures for May, which saw a 14.9% fall. Nonetheless, analysts at IHS Automotive expect British manufacturing to be bolstered by booming sales in emerging countries such as China, with total car production rising by 10% to 1.4m units.

Nissan said 5,000 employees would work over the weekend in Japan to take the strain off the Japanese grid, which has suffered a severe loss of supply after the Fukushima nuclear disaster.

A cut in peak demand during the week is expected to help Japanese electricity suppliers as they wrestle with the loss of power from Fukushima and several other power stations affected by the 11 March earthquake and tsunami. Electricity use across Japan is at its lowest at the weekend.

Toshiyuki Shiga, the company's chief operating officer, said the entire industry would make the shift to weekend working to prevent the electricity system from failing during peak periods.

He said: "It is something we must do if there is to be a 15% saving on electricity consumption on top of the savings that have already been made, which is what the government is seeking."

He added: "It is a problem because we face a backlog of orders from the US and Europe following the disruption to the supply chain. So a new Saturday-to-Wednesday regime needs to produce more cars than usual while satisfying the need to cut electricity."

The fallout from the earthquake and the sharp reduction in electricity supply has made many Japanese companies gloomy about the economy this year.

A twice-yearly survey by the Asahi Shimbun newspaper found that close to half of the executives polled at 100 companies believed the economy was heading downhill.

Masami Yamamoto, president of the electronics multinational Fujitsu, told the paper: "The disasters threw cold water on the entire economy."

Businesses have complained to the administration of prime minister Naoto Kan that it needs to act quickly to rebuild the worst-affected areas along the eastern seaboard and resolve the country's electricity supply issues. Only 17 of the country's 56 nuclear plants are working, with many offline for repairs after the tsunami or for regular maintenance.

Businesses fear many will be prevented from coming back into use by local authorities, which have jurisdiction over local power plants. A further 12 new plants are expected to be scrapped following pressure from local groups.

As in Germany, the crisis at the Fukushima plant has sparked a public backlash against nuclear power. The Kan government has demanded a major shift to renewable energy, with a plan for solar panels on 10m homes over 10 years. But businesses are concerned this is too ambitious and will not satisfy industry's immediate energy demands.

One industry source said: "It is fine for Germany to say it no longer wants to build nuclear power plants because it can buy electricity from France, but who can we buy from? There is no one. The only answer will be to import more oil, and where does that leave our plans to cut C02 emissions?"

Office buildings across the country have turned down the settings on air conditioning, reduced the number of lifts in service and switched off lights in corridors to cut demand for power.