The Supreme Court on Tuesday struck down as unconstitutional a Central government notification that says a complainant must prove that the accused person is of foreign origin.
A bench comprising Justices S B Sinha and Markandeya Katju also directed the Union government to constitute sufficient number of tribunals to detect alleged infiltration of thousands of Bangladeshis into Assam.
The opposition Asom Gana Parishad hailed Tuesday's Supreme Court's decision on the foreigners issue as a "great victory for the people of Assam".
"It is a great victory for the people of Assam and has brought an end to the move by the Centre and Congress government in the state to get back the controversial Illegal Migrants (determination by tribunal) Act through the backdoor," AGP member of Parliament Sarbananda Sonowal told reporters in Guwahati.
Sonowal, who filed the affidavit against the IMDT, which led the apex court to scrap the act in 2005, said within a month of the verdict the Centre's group of ministers led by Pranab Mukherjee framed the notification fixing the onus of proving a particular person to be a foreigner on the complainant.
With the scrapping of the act, it was the duty of the person alleged to be a foreigner to prove his credentials, but the move of the Congress "was to hoodwink the people of Assam and appease their minority vote bank," he alleged.
Tuesday's SC decision has proved that the Centre cannot "fool the people of the state time and again and now they are politically aware of their rights," the AGP MP said.
The Assam state unit of the Bharatiya Janata Party demanded the resignation of the Congress-led United Progressive Alliance government after the SC struck down the notification as "unconstitutional".
"The apex court has again proved the decision of the state and Centre wrong and thus the UPA government should resign owning moral responsibility," BJP state unit president Ramen Deka said.
The BJP leader accused the Congress government of attempting to bring in the scrapped IMDT Act through the backdoor by the notification.
"The BJP would oppose any move by the Centre which went against the interest of the state," he said.
The AGP leader launched a scathing attack on the UPA government at the Centre and state government for not abiding by the decision of the apex court to constitute the tribunals within four months of the verdict scrapping the IMDT.
"The tribunals have not been formed and on the other hand, the notification was made but with the apex court's verdict (to strike down the notification) it has been proved that no illegal laws can be imposed on the people of the state," he said.
"The Congress should learn a lesson from this and refrain from such acts," he said.
On the updating of the National Registrar of Citizens, the AGP MP alleged that both the Centre and state government "are not showing sincerity in completing the proces."
The work on updating the NRC should be expedited and completed soon, he said.