Last year Santi remarried under another private nikah siri. She now has a newborn child and lives in Bali. But she is worried that her new husband may one day leave her, too.

In the populous neighbourhood of Tebet Barat in Jakarta, Masruhatin has good days and bad. She had been married to Agus for a few years when, one day, he returned home with a new bride. The younger woman had become pregnant while she was having an affair with Agus. Although the law would have required it, Masruhatin never consented to her husband marrying again and had little option but to accept the new wife.

Agus, who claims to be a Christian and to have received 'special indulgence from the bishop', has taken advantage of cultural traits that keep polygamy legal in Indonesia, although only among the Islamic community.

Santi and Masruhatin are not alone. Although reliable data does not exist, activists believe hundreds of thousands of women are either married under nikah siri or live in a polygamous marriage against their choice. Often, one reinforces the other, with nikah siri used as a shortcut to avoid the rule of polygamy - or the blemish of adultery.

The government-sponsored 'religious court on marriage bill' could mitigate the problem. It needs the endorsement of President Susilo Bambang Yudhoyono and the House of Representatives to become law. If ratified, it would make nikah siri illegal and demand that all would-be polygamists get written consent from their spouse/s and prove they are financially capable of providing for all of them. Any breaches could lead to a three-month jail term and a 5 million rupiah (HK$3,250) fine.

At this juncture, however, many wonder whether the bill goes far enough or will even make it into law.

Leading Muslim intellectual Siti Musdah Mulia said it would not protect women and children. She told The Jakarta Post that 'the penalties facing offenders are too weak to deter men from proposing unregistered, contractual or polygamous marriages'.

Masruchah, secretary general of the Indonesian Women's Coalition for Justice and Democracy, was more upbeat, however. 'We have long supported the regulation of these practices and it is pleasing to see that the government is acting on it,' said the activist, who like most Indonesians only has one name.

She also argues that nikah siri dehumanises women and treats them as commodities, while polygamy is associated with violence and violation of rights. 'We need to educate people. We need to explain that these practices are unfair to women and children,' she said.

Sri Nur Herwati, from the Legal Aid Foundation of the Indonesian Women's Association for Justice, said the bill was a step in the right direction but that there was also a need to change the Law on Marriage - the root of the problem.

She also rejected the concept of religion influencing the rule of law. 'The government needs to separate between the law and religious issues. This is only a problem because the government has failed to make the content of the law known [among the population]. Therefore, people think that religion regulates these subjects.'

Mrs Sri also disclosed that, according to data gathered by her NGO, polygamy is on the rise in Indonesia. 'In 2008, we received 87 reports of polygamy, while in the previous year we received only 16.'

This number is thought to be just the tip of the iceberg because, as noted, most polygamists fail to register their second or third wives.

Activists, however, agree that the toughest hurdle is the reaction of the Islamic community, where the initial response was quite conciliatory regarding the abolition of nikah siri but opposed to the idea of further regulating polygamy.

Generally, Islamists argue that polygamy is sanctioned by the Koran and prevents adultery, while moderates see it as contradictory to reform and an attempt to impose snippets of Islamic law on a secular society. Moderates also point out that the Prophet Mohammed had a happy, 28-year monogamous life with Khadijah and rejected his son-in-law's request to become polygamous.

Abu Bakar Bashir, a radical Islamic cleric, largely considered the spiritual leader of terror group Jemaah Islamiah, said that 'whoever doesn't want their marriage to be [publicly] known is a coward' and called on the state to 'immediately take action and stop this kind of arrangement'.

'If a man wants to practise polygamy, he should have good intentions and treat his wives in a just manner,' he told the Indonesian news agency Antara.

The leaders of the two largest moderate Islamic organisations have been very coy about the issue. Muhammadiyah chairman Din Syamsuddin called for caution in passing such a bill into law, to avoid violating religious principles. The deputy chairman of Nahdlatul Ulama, Masdar Farid Mas'udi, refrained from comment.

Anwar Ibrahim, head of the fatwa commission of the Indonesian Ulama Council - an entity partly founded by the government, and considered the country's highest Islamic institution - said that nikah siri was not recognised by Islam if the ritual was performed in secret. But he said polygamy was a way to make sure that a man's needs, particularly sexual, were satisfied.

Ida Ruwaida Noor, a sociologist at the University of Indonesia, stressed that cultural traits among women were also important in shaping the acceptance of, and the debate about, nikah siri and polygamy.

'From a socio-cultural approach, women in Indonesia still largely see their role as being a wife and a mother,' he said. 'So, for some women, it is better to be someone's second or third wife than to be unmarried. Also, if they cannot have children, they may prefer that another wife brings children into the home, rather than having no children at all.'

Historically, however, while nikah siri seems to have been largely tolerated, Indonesians have taken a conflicting approach to polygamy.

Sukarno, Indonesia's founding father, had four legal wives, with polygamists arguing that he was carrying on the legacy of Java's sultans. His successor, the autocratic Suharto, on the other hand, imposed a ban on polygamy for civil servants during his 32-year rule. When his regime ended in 1998, the resurgence of a more vociferous Islam led to a more open practice of polygamy, although not necessarily a widespread acceptance.

In 2001, former vice-president Hamzah Haz's polygamy was frowned upon. The leader of an Islamic party, Mr Hamzah had three wives and was accompanied by his first wife to official events.

But the debate really exploded in 2006, when Abdullah Gymnastiar, once Indonesia's most respected star cleric, announced his decision to take a former model as his second wife. He was seen by many as a model husband and a promoter of family values, and his decision alienated his followers. His career nose-dived, as women openly rejected his lifestyle.

Dr Susilo reacted by extending the ban on polygamy to cover all lawmakers, ministers and other government officials. The legality of the practice was then tested a year later, when a Jakarta businessman asked the Constitutional Court to delete the requirements for practising polygamy.

Muhammad Isa claimed the requirements violated his religious rights and that the restriction pushed men to practise nikah siri instead of registering their second marriages. The court, however, ruled that 'the articles are neither against the tenets of Islam nor the country's constitution and are intended to protect the basic rights of current and prospective wives of men who engage in polygamy'.

Some of the names of the people quoted have been changed to protect their privacy.