Lukman and Niti are among many illegal migrants still in Malaysia

Hundreds of thousands have already left the country, but others are determined to remain.

The BBC's Malaysia correspondent, Jonathan Kent, spoke to migrants who have chosen to stay, and to one of nearly 300,000 volunteer reservists and immigration officers have been tasked with tracking them down.

Lukman is not going anywhere. Forget the crackdown, he wants his money.

He comes from a village on the Indonesian island of Java - a place with too few jobs and even less hope.

"I came to Malaysia because there are more opportunities here," Lukman said.

For people with next to nothing, Malaysia is a promised land.

The Indonesian newspapers carry stories of domestic maids who earn what to a Malaysian is a paltry $100 a month, but return home after a few years to build their dream home.

We have no chance of an education and I can't rely on my brother to provide me food. That's why I have to come to Malaysia Niti, Indonesian migrant

Millions of Indonesians board boats to Malaysia, often paying agents large sums to get them legal work.

"With the current employment agency system, which would cost me $800 to $1000, I can't afford it," he said.

"Because of that system, created by the government, I have no other choice than to come to Malaysia on a tourist visa."

Niti is just 21, seven years younger than Lukman. Despite her slight stature, she works alongside the men who are putting up a complex of high rise apartments near Sungai Buloh, on the outskirts of Kuala Lumpur.

"Every day I work on the construction site. I have to carry the cement, open it up and pour it out for the men to mix," she said.

But even when the men have finished their working day, Niti labours on. "After work I still have to do the cooking for them at the 'kongsi' [workers' accommodation]. At any one time I have to serve the food for 30 male workers who live with us," she said.

Nor does she even receive the $200 a month the men get - she works for her food and keep alone.

No choice

"I come from a very poor village in Madura, with seven siblings. My father is a farmer and we live in extremely bad conditions. Our house is something like the makeshift home on the construction site here - we have no electricity, nothing," she said.

"We have no chance of an education and I can't rely on my brother to provide me food. That's why I have to come to Malaysia."

Lukman and Niti are just the sort of people Malaysia's immigration department wants to round up.

Lukman and Niti live in basic on-site accommodation

But rather than keep a low profile until Ops Tegas - the name of the government's drive to round up illegal workers - runs its course, they are standing their ground very publicly and demanding wages they say they are owed.

According to Lukman, they have only been given some 40% of the small sum they were promised. Their employer says the rest went to a subcontractor who ran off with the cash.

"In the process of trying to get our rightful wages, our employer has done many inhumane things to us," said Lukman.

"They tried to create trouble among us, our shacks were torn down, our food supply from the canteen was stopped, and they also set hunting dogs on us and tried to chase us out," he said.

"The site manager also tried to hire some of the other illegal workers, armed them and tried to get the different ethnic groups to fight one another."

Lukman and his fellow workers' plight has become something of a cause celebre in Indonesia.

The government in Jakarta threatened to hire lawyers to take Lukman's and other employers to court, but were dissuaded by the Malaysian authorities, who said the issue would be resolved.

Lukman is not convinced. "Our president came here to seek help from the Malaysian government to get the employers to pay the wages due to us. But no positive action has been taken, so we're still waiting and hoping," he said.

A taxi driver by day, Peter has been in Rela, Malaysia's volunteer reserve, for almost five years.

"Usually when they need us they'll call us to go for duty," he said. "Sometimes... we go together with the immigration [officers] to pick up those illegal foreigners."

Peter sees his volunteer work as his national duty

He and the 300,000 other members of the reserve are supposed to go for weekly training sessions.

"We go marching every Saturday, and shooting with the M16 [assault rifle]," he said.

For Peter, playing his role in the reserves is his contribution to the country's safety.

With hundreds of thousands of foreigners living outside the law and widely blamed for rising crime, he sees the job of rounding them up as a social duty.

"Especially the illegal immigrants for Indonesia, they always give us a lot of trouble. They break into the house, they rob, they steal everything," he said.

"Most Malaysians worry about it."

Being a volunteer is not easy. According to Peter, encounters with illegal immigrants can often be dangerous.

"Sometimes they jump from three storeys, two storeys, they even go through the drains," he said.

"We don't carry weapons, we just carry a stick to protect ourselves in case they carry knives. Sometimes they carry a parang - a knife [machete]."

But like most Malaysians, Peter is aware that foreign labourers, legal and illegal, do jobs that he and his fellow citizens would not dirty their hands with.

He has some sympathy for genuine workers.

"Some of them they really work here, so sometimes when they work here we give them a chance because we are human beings - we let them go."