After a lull of more than a year, the Supreme Court on Tuesday commenced the hearing to examine the constitutional validity of the controversial amendment to the law on Office of Profit with those against it accusing the government of "starting a dangerous trend".

"The amendment in the act was brought to protect 40 MPs from disqualification. The desire of bringing an amendment with retrospective effect raises an important question of propriety," senior advocate Harish Salve submitted before a Bench headed by Chief Justice K G Balakrishnan.

Salve, who appeared for Trinamool Congress MP Dinesh Trivedi, said it was a colourable exercise of power to protect some big faces who were supporting the government.

"Like everybody supporting the government becomes a minister, the amendment to the law on the office of profit makes anyone supporting the government become chairman of an office," he said.

The two separate petitions filed by Trivedi and an NGO, Consumer Education and Research Society has challenged the Parliament (Prevention of Disqualification) Amendment Act on the office of profit alleging that it was passed with retrospective effect solely to protect about 40 sitting members of Parliament.

When the law was passed all those members were facing disqualification proceedings before the Election Commission.

Salve said the wholly arbitrary and discriminatory act was passed in undue haste and without seriously addressing any of the concerns raised by the then president A P J Abdul Kalam, who on May 31, 2006, had returned the bill to Parliament for reconsideration.

"How often the President in this country sends a bill for reconsideration. In recent times, it has happened only on two occasions," the senior advocate said adding, "the law is in brazen defiance of the Constitution".

"Forty members of Parliament were to be affected. That is why the bill with the amendment was introduced. This is a very dangerous trend," he said.

The petitions alleged that the act has been enacted in self-interest and not in public interest as each one of the offices which have been exempted by it have a face behind it.

Nearly 45 offices of profit were exempted by the act with retrospective effect from the year 1959, a large number of them came into existence after that year.

At the time of filing of the petitions in August and September 2006, among the 40 MPs, Lok Sabha Speaker Somnath Chatterjee held the office of chairperson of the Santiniketan-Sriniketan Development Board and Samajwadi Party MP Amar Singh held the post of the chairman of Uttar Pradesh Industrial Development Council.

It has been contended that the Amendment Act was violative of Article 14, 102(1)(a) and 103 of the Constitution.