"All of us are urged to leave our cars at home," said Zhou Qing, a spokesman with the National Development and Reform Commission.

"We are encouraged to walk or take public transport to work."

And temperatures will rise in the offices of the nation's top economic planning authority today, as the air conditioning shuts down for the day. "We hope our individual actions will help solve China's energy shortage," said Zhou.

Following in the commission's footsteps nearly all government departments and agencies in Beijing have ordered their employees to follow suit.

But some will find the power-saving regime difficult to implement.

"To keep our equipment in normal working condition it's not possible for us to turn off the air conditioning system for a day," said Wang Caiyun, director of the energy-saving office of the State Administration of Radio, Film and Television.

"But we will keep office temperatures at or above 26°C," she promised.

The Government Offices Administration of the State Council said public servants are some of the biggest power users.

A survey quoted by Guangming Daily last year claimed that civil servants' per capita water and electricity use in Beijing was three to seven times that of ordinary residents.

China's nearly 7 million public servants reportedly use almost 5% of the country's annual electricity consumption enough to meet the demands of 780 million farmers.

"We have a lot of room for improvement in electricity efficiency in lighting, air conditioning, computers and other office equipment," said Jiao Huancheng, director of the government offices administration.

"Public servants at central government level should set a good example."

Experts warned that the campaign should not become a "one-day show," and called for energy saving to become part of everyday life.

"Saving energy and resources is a long-term task that calls for more than one-off measures," said Lin Yueqin, a researcher with the Chinese Academy of Social Sciences.

He said consistent and systematic policies and laws were needed to encourage efficient use of energy and resources.