By Subir Bhaumik BBC correspondent in Guwahati

BJP campaigners say illegal immigration must stop

The north-eastern state will be voting for 14 parliamentary seats during India's forthcoming general elections.

Now the emotive issue of alleged illegal migration from Bangladesh, which has caused much bloodshed and agitation in Assam during the past 25 years, has surfaced again.

India's governing BJP and the regional Asom Gana Parishad (AGP) are raising the issue in their campaigns.

Migrants law

"The illegal migrants from Bangladesh constitute the single largest vote-bank for the national parties in Assam. So everyone tries to appease them.

The [Illegal Migrants] Act protects the infiltrators from Bangladesh and helps them stay in Assam Samujjal Bhattacharya, All Assam Students' Union

"But we will not tolerate that and we will do everything to scrap the law that helps them stay in Assam," says Samujjal Bhattacharya, who leads the All Assam Students' Union (AASU).

The AASU led violent anti-migrant protests in the early 1980s, which degenerated into riots and arson.

Some 4,000 people, mostly Hindus and Muslims of Bengali origin, died.

Although it does not contest elections, the AASU has much clout in Assam's politics.

Mr Bhattacharya told the BBC the AASU had asked all parties running in Assam to make their position clear about the Illegal Migrants Act that was created in 1983 by the then ruling Congress party.

The act provides a legal framework to detect and deport illegal immigrants, but its opponents say it does the opposite.

"This act protects the infiltrators from Bangladesh and helps them stay in Assam. It makes it difficult for law enforcing agencies to detect and deport them," Mr Bhattacharya alleged.

"This act must go."

Both the BJP and the AGP, which grew out of the anti-migrant campaign and ruled Assam for 10 years, oppose the act and want it scrapped.

A bill was introduced in the federal parliament to do just this two years ago but it fell through.

Campaign issue

Both parties are raising the migrant issue again.

During a recent rally in Assam, Prime Minister Atal Behari Vajpayee said "illegal immigration is a major problem for Assam and must be stopped".

The Congress which rules Assam and the United Minorities Forum (UMF) as well as other minority parties want the law to stay.

Assam's chief minister, Tarun Gogoi, told the BBC that though some illegal migration continued to take place from Bangladesh, it was not on as massive a scale as alleged.

They are paranoid about any non-Assamese and feel all of them are foreigners even though we speak their language and respect their sentiments Hafiz Rashid Ahmed Choudhury, United Minorities Forum

The UMF's president, Hafiz Rashid Ahmed Choudhury, says the Illegal Migrants Act "is the best safeguard for the Indian minorities in Assam".

"Otherwise the local administration will pull out any Bengali-speaking Hindu or Muslim family and push them into Bangladesh.

"They are paranoid about any non-Assamese and feel all of them are foreigners even though we speak their language and respect their sentiments. That many of us have lived in Assam for two or three generations does not help," he says.

But Assam's demography has changed over the last century and that has made the ethnic Assamese apprehensive about losing their identity and culture.

"Bengali Muslims are almost 30% of Assam's total population now and Bengali Hindus are another 15% of the population. So we are nearly half the total population of the state," Mr Choudhury adds.

Numbers dispute

Some analysts say the migrant issue has lost much of its sting in Assam's politics because the AGP failed to throw out the illegal migrants or the so-called foreigners.

"The AGP failed miserably after it came to power riding the anti-migrant wave in 1985," says local political scientist Sanjib Baruah.

Bhupen Hazarika, a popular Assam singer, campaigning for the BJP

"During its tenure in government, it could detect only a few thousand illegal migrants and deport still much less. So people stopped taking their claims seriously."

Others say illegal migration from Bangladesh has slowed down if not stopped.

"The last three censuses in Assam show the state's population growth rate has been less than the national average. If there was large-scale infiltration from Bangladesh, it would have been reflected in the census," says Chief Minister Tarun Gogoi.

India's Deputy Prime Minister, LK Advani, alleged last year that there were up to 20 million illegal migrants from Bangladesh in various parts of India - many of them in Assam and the neighbouring state of West Bengal.