TOKYO, 2 June 2006 - Japan kicked off its summer "Cool Biz" casual clothing campaign on Thursday with politicians ditching their suits and ties to encourage the nation to use less air-conditioning.

The government has again asked both private and public sector workers to dress lightly and set the temperature of their air-conditioned offices no lower than 28ËšC during the sticky summer months.

Prime Minister Junichiro Koizumi has pledged to discard his tie throughout the summer campaign, except when meeting foreign dignitaries.

"It feels nice not having to wear a tie," Koizumi said as he emerged from his Tokyo residence dressed in a loose Okinawan-style white shirt, Kyodo News reported.

In 2005, the first Cool Biz drive helped cut carbon dioxide emissions by 460,000 tonnes - equivalent to the combined emissions from one million Japanese households per month, the government said.

About one-third of company offices said they had significantly reduced the use of air-conditioning after last year's drive, leaving room for improvement.

On Wednesday night the environment ministry hosted a fashion event at Omotesando Hills, an ultra-glitzy new shopping mall, in collaboration with other Asian nations to push the anti-climate change message.

Japan's foreign and finance ministers as well as the ambassadors of China, South Korea, the Philippines and Thailand took to the catwalk to model casual business attire from the likes of Louis Vuitton and Giorgio Armani.

However, not everyone was heeding the government's call.

"Personally, I don't like to wear ties. But since that's the way it has always been done, I can't do otherwise," said one 23-year-old office worker dressed in a black suit and light-blue tie on his lunch break in central Tokyo.

Some older businessmen are particularly reluctant to ditch the tie.

"Neckties strangle me," joked one 64 year old, "but since I work in a major company, they're a symbol of status."

Japan, host of the famous 1997 Kyoto Protocol on climate change, has launched a series of energy-saving measures as it struggles to stay on track to meet its commitment to cut greenhouse gas emissions by six per cent from 1990 levels by 2012.

The latest campaign offers a lucrative sales opportunity for Japanese retailers, but not everyone is happy - last year tie-makers saw sales slump during the summer months.