The sky is still dark when the flood starts. It begins with a trickle, a handful of young people walking to work in the concrete landscape of Vattanac Industrial Park in a dusty corner of Phnom Penh.
But suddenly, just as the sun rises, the wide access road running between the factories on either side is awash with a tide of thousands.
They arrive on trucks jam-packed with dozens standing on the flatbed, or perched on wooden trailers pulled behind motorbikes. As they disembark, the scene is reminiscent of a pre-match football crowd, everyone walking with purpose to a common destination.
The women wear headscarves, the much smaller number of young men sport baseball caps. All have ID cards swinging around their necks, identifying the factories they work for.
For the rest of the day they will take their places at sewing machines, steam irons and sorting tables, producing clothes for some of the world's best-known labels: Gap, H&M, Adidas, Puma.
From a standing start in 2000, the garment industry has grown to the point where, at peak periods, more than 400,000 people work in the factories.
It is the country's biggest employer and key export earner. And the cash which workers send home to their families has helped to improve the quality of life in rural provinces.
But now there are signs that a garment factory job is losing some of its allure. The industry recently admitted that as many as 50,000 recent vacancies had gone unfilled.
Increasing numbers of young people are willing to take their chances as migrant workers in other countries.
Even though there are reports of mistreatment of domestic staff in Malaysia and fisheries workers in Thailand, they are balanced against the financial rewards - and the money usually wins.
'Difficult to afford'
One of the main reasons the workers are turning their backs on the sector is the complaint that wages have not kept pace with the rising cost of living.
As they stop to grab breakfast at the food stalls - noodle soup or pork and rice, costing just 25 cents (16p) - outside the factories, many workers say even that is more than they can afford these days.
"It's difficult for me to afford food and rent for a place to live," says 25-year-old Sok Asry, as she heads towards the factory gates.
"If they could increase the wage to more than $100 (a month) that would be great," says her 27-year-old colleague, Eam Him.
The minimum wage guarantee has long been part of Cambodia's strategy for the garment industry. It currently stands at $61 per month, though standard allowances raise that to more than $70 for all employees.
That is one part of a range of safeguards designed to prevent the exploitation of workers. Among other provisions, the Labour Law guarantees union rights, prohibits the use of underage workers and allows nursing mothers to take breastfeeding breaks.
A monitoring programme overseen by the International Labour Organisation makes sure that factories follow the rules.
These measures have made Cambodia enormously attractive to buyers from big-name companies looking to source clothes untainted by association with the kind of sweatshop labour which attracts consumer boycotts.
Salaries were also the concern of a "people's tribunal", an informal event organised by unions and rights organisations to look into the workers' concerns.
After hearing from workers and buyers alike, it declared that a garment worker's minimum pay no longer represented a living wage.
The Asia Floor Wage Alliance - a union-based group which campaigns for fair pay across the region - reckons that $281 a month would represent a living wage for the average Cambodian garment factory worker.
That would be a four-fold increase on the current minimum, and - according to industry representatives - would pose a major problem for the factories.
"If wages were increased without any relevance or linkage to other factors, that's going to be detrimental," says Ken Loo, the general secretary of the Garment Manufacturers' Association of Cambodia.
"If there was a direct correlation to productivity, and wages increased because of that increased productivity, then everybody would be better off."
The industry is undoubtedly caught in a delicate balancing act. Buyers may be keen on Cambodia's image as an ethically sound production base. But they still put pressure on the factories to keep their prices low, and the owners are keenly aware that other countries offer cheaper options.
The UK-based pressure group Labour Behind The Label hopes that big name buyers will work together to reach agreement on living wages - and accept that the price they pay may have to rise.
But that would depend on the willingness of consumers around the world to spend more on their clothes. Given the current world economic situation, such altruism may be in short supply.