Newly rich Chinese have spent the May Day holiday, a time to celebrate the international labour movement, opening their wallets in far-flung destinations.

This week's May Day "golden week" is one of three week-long national holidays and the government expects a record high 120 million trips taken by Chinese tourists, at home and abroad.

"If past trends hold true, they will likely spend more than 40 billion yuan ($5 billion)," Xinhua news agency said.

Up until the mid-1990s, workers in China used to put in six-day working weeks and only had a long weekend or two off during the year.

"Now, if all weekends and holidays are counted, workers can enjoy up to 114 days off... about a third of the year is spent in leisure time," Xinhua said.

"In a nation that for thousands of years held diligence and hard work in the highest esteem, the Chinese have learned to relax, travel and loosen their wallets."

The current May Day holiday, Chinese Lunar New Year and National Day spur one of the world's biggest migrations of humanity as millions travel to their home towns, domestic tourist spots or, increasingly, abroad.

"When the first golden week holiday was initiated on a trial basis, to celebrate National Day in October 1999, China was astonished to see Chinese tourists take 28 million person trips while spending 14.1 billion yuan," Xinhua said.

"Tourists in China, nevertheless, have seemingly never looked back since that first full week off."

The World Tourism Organisation estimates that every tourist dollar will generate 4.3 times that amount in economic spin-off.

"This would mean the country's golden weeks have been worth over 2 trillion yuan to the Chinese economy," Xinhua said.

But while the economy gains, China's press has played up the plight of migrant workers, who have fuelled much of the country's rapid economic development by providing the workforce for its factories and its construction boom.

In past years, some of the estimated 100 million farmers who have moved to booming cities to find work have been unable to go home for the Lunar New Year holidays because they had not been paid in months.

A series of suicides and violent attacks committed by desperate unpaid migrants has drawn attention to their fate and Premier Wen Jiabao told parliament in March China would channel its surging economic growth to narrow the widening gap between the country's rich cities and restive countryside.