New Delhi, India (CNN) -- Angry protests disrupted India's parliament several times Monday over a landmark but contentious bill aimed at reserving one-third of seats for women in federal and state legislatures.
India's governing party, the main Hindu nationalist opposition party, and the Communists came together in a bid to push the long-pending legislation through the upper house of parliament on International Women's Day.
But a small group of politicians, opposed to what is commonly referred to as the "women's reservation bill," fought it tooth and nail. Critics of the bill, which was first introduced more than a decade ago, have been demanding a sub-quota for the most disadvantaged women and for Muslim women.
Slogan-shouting lawmakers from at least two regional groupings, the Samajwadi Party and the Rashtriya Janata Dal, forced several adjournments of the chamber Monday.
The two parties announced withdrawal of their support from the government coalition over their row, and their leaders marched on India's sandstone parliament building along side party members in protest.
The protests forced the upper house to suspend its activity for the day, so the earliest the bill could pass is now Tuesday, when the session resumes.
Political analysts said the small but fierce opposition to bill was a sign of a duel between the country's regional and national politicians.
"This opposition is about regional politicians trying to preserve their regional monopolies," remarked Zoya Hasan, a professor of political science at New Delhi's Jawaharlal Nehru University.
There was no immediate risk to the ruling coalition, but it did lose more than two dozen supporting lawmakers in the lower house with the two parties pulling out.
"This leaves the government on a razor-thin majority," Hasan said.
India's governing Congress Party, a national group headed by Sonia Gandhi, won 206 of 543 boroughs of the federal parliament last year to retain power for a second term.
Its 2009 performance was its best performance since 1991 in a country that has been governed by coalition governments for most of the past two decades.
The country has a female president, Pratibha Devisingh Patil, who in 2007 became the first woman elected to the post. The leader of the opposition in the lower house, Sushma Swaraj, and the speaker of the lower house, Meira Kumar, are also women, as is Congress leader Gandhi.
But women make up just 11 percent of the members of the lower house, or the Lok Sabha, of the Indian parliament.
In rural India, they constitute about 40 percent of all elected heads of village councils.
On Saturday, Indian Prime Minister Manmohan Singh vowed greater female representation in the country's democratic process.
"As we approach the International Women's Day, let me once again reaffirm our government's commitment to all-round social, economic and political empowerment of our women, whatever effort and resources the task might take," he said New Delhi.
Half of India's female population cannot read or write, authorities say.
The South Asian nation of more than 1.1 billion people also has a skewed gender ratio, with 933 women for every 1,000 men.
"What is even more a matter of concern is that the child sex ratio in the age-group 0-6 years has declined from 962 females (for every 1,000 men) in 1981 to 927 in 2001," Singh said.
If the women's bill is approved by the House of Elders, the legislation goes to the lower chamber. If it is approved there, a presidential assent would turn it into law.
India holds its next general election in 2014, but many state elections will be held before then.
The country lies in the Asia-Pacific region which has next to the fewest female lawmakers in the world, according to the United Nations.
Asia-Pacific women hold only a handful of legislative seats, fewer than anywhere else except in the Arab region of the Middle East, according to Monday's Asia-Pacific Human Development Report. The Pacific sub-region accounts for four of the world's six countries without any women lawmakers.