The seamstress, who is paid little for the eight-hour day she spends cutting cuffs for branded shirts, was forced to call on money lenders to keep her children in school.

Now she is among tens of thousands of workers in India's $40 billion-a-year textile and garment industry who are seeking higher wages from the factories that supply global brands.

"May-June is the month that we regularly take a big loan to pay children's fees, buy new uniforms and books," said Kumar.

"My daughter's college also asked for a donation. It all came from borrowed money. I want them to study but there are days it looks impossible."

Despite minimum wage laws, salaries continue to be "grossly low" for thousands of workers, many of whom are still not given pay slips or are only hired as apprentices, campaigners say.

Kumar has a take-home salary of 7,000 Indian rupees ($103) and has to repay loans worth more than 200,000 rupees ($2,957).

"Everyone is indebted and it is a vicious cycle of never-ending loans," said Sujata Mody of Penn Thozhilalargal Sangam, a Chennai-based women workers' union.

"The women in this industry are constantly borrowing money from someone to pay back someone else."

An estimated 45 million workers, mostly women, are employed in India's thriving garment industry, with major hubs in the southern states of Tamil Nadu and Karnataka.

The clothes they stitch are exported around the world and sold by big brands, which have long promised better conditions in their supply chain.

Promises aside, campaigners say little has changed, with low wages, verbal and sexual harassment and long hours the norm.

A year-long study of more than 500 workers in Cambodia, India and Bangladesh found women often work overtime or borrow money just to feed their families and pay rent.

Despite earning the minimum wage and logging overtime, researchers found most were still short of money.

WHICH CHILD?

It was a tough decision for Savita Rajesh to end her teenager's schooling this year.

But with mounting debt and no increase in her wages or festival bonus, the seamstress said she had no choice.

For 12 years, the 35-year-old has stitched shirts and blouses for leading fashion brands and takes home 8,500 Indian rupees ($126) a month.

"My elder daughter passed out of grade 10 but will not go back for further studies this session. It's not about whether I want it or not. It's about not being able to afford it," Kumar told the Thomson Reuters Foundation.

"The garment factory my husband worked in closed without notice a few months back. He is still unemployed. We took a loan of 20,000 rupees for the younger daughter's fees and books. The interest is already mounting."

The pressure to repay forces most workers to resign every few years so they can access their factory's employee saving fund, union leaders said.

"Then they rejoin the workforce but are treated as new employees and start at the bottom again, foregoing benefits of permanent workers," said Saroja Kannappa of the Garment Labour Union, which represents more than 4,000 workers.

"There is no financial security at all, even for women who have spent 20 years stitching clothes for big brands."

Unions and campaigners want a living wage, saying the minimum wage set by most Asian countries is inadequate to ward off poverty, they say.

More than 1,000 people joined a rally on May 1 in Bengaluru, carrying placards reminding brands of their promise to pay a living wage to all workers in their supply chain.

In Chennai, workers are fighting lengthy court battles to get their dues, two years after the Madras High Court said they should receive a pay rise of up to 30 percent - the first minimum wage hike in 12 years.

"Everyday is a struggle," said Rukumini V. Puttaswamy, a tailor for 17 years and now head of the Garment Labour Union.

"Cost of living for workers, many of whom are single mothers, in cities like Bengaluru is very high. Rents are high and education is very costly. There is no choice but to borrow money and constantly work to pay it off."