Protesting against the bill, adopted by a voice vote, CPI(M) leader Somnath Chatterjee led the walkout saying "mistaken notions" about the World Trade Organisation (WTO) had led the Government to take this "anti-national" measure.

Earlier, the house rejected certain opposition-sponsored amendments by a division of 54 to 231 votes with one abstention.

Replying to the two-day-long debate on the bill, as approved by the Rajya Sabha, industry minister Sikander Bakht assured that national interests would not be compromised at any cost and assured that product patenting would not be permitted before 2005.

Bakht said that India could take a u-turn from the WTO due to the previous Governments'commitments and added that efforts would be made by the present regime to keep the interests of the country intact in the global arena.

"Without going into the global playing field, we cannot protect our national interest," he said, emphasising that no country would be allowed to play with India's bio-diversity and plant variety.

Stating that the EMR Bill contained adequate safeguards relating to pricing, compulsory licensing, and powers to revoke EMR licences in national interest, Bakht said that the Government would take political parties into confidence before bringing a comprehensive bill on product patenting.

Replying to points raised by members from opposition benches regarding the pharmaceutical allies, he said that the Government wanted this industry to be restructured.

For this purpose, a committee comprising competent scientists had been set up to advise the Government on the entire process and on how to patent medicinal products. About 3,000 applications were pending with the Government forproduct patenting, he said.

Before the passage of the bill, Chatterjee appealed to Prime Minister Atal Bihari Vajpayee and his cabinet colleagues to reconsider it "before the final damage is done".

The treasury benches opposed the remark by the CPI(M) leader that the bill was "anti-national", with the industry minister urging Chatterjee to withdraw the comment.

Chatterjee said that he was not doubting the patriotism of the ruling party members but "the mistaken understanding of the WTO had resulted in this anti-national measure", as it conceded rights to foreigners to the detriment of national interests.

Besides the CPI(M) and CPI, members of other Left parties, RJD and Samajwadi Party also staged a noisy walkout.

Throughout the melee, Congress members remained silent spectators even when there was a procedural wrangling over division relating to certain clauses of the bill.

While the opposition members had demanded a division on amendments to clause 8 relating to protection of security of India,speaker GMC Balayogi announced it as adopted on voice vote.

Later, certain amendments moved by Basudev Achariya (CPI-M) were rejected through a division of votes.

The house earlier negated a statutory motion by VV Raghavan of the CPI for disapproving the ordinance which this bill sought to replace.

During the discussion, a member of the ruling coalition Kailaso Devi (HVP) opposed the bill saying it would harm national interests and charged the BJP with "treason for selfish interests".