In a seemingly unprecedented move, all newly-elected legislators in West Bengal have given a "written declaration" on stamp paper that they would not leave the party, a party leader said on Tuesday.

The emerged as the main opposition party in the recent Assembly elections bagging 44 seats in the 294-member house.

The members gave the declaration on non-judicial stamp papers valued at Rs.100.

In the "affidavit to the president", all the lawmakers swore their "unqualified allegiance" to the party, led by its president Sonia Gandhi and vice president Rahul Gandhi.

They gave an undertaking that they would abide by all the decisions taken by the party, and obey the directives of the chief whip in the assembly.

They also resolved not to make any anti-party remarks and affirmed they would resign their membership of the assembly before opposing any decisions taken by the party.

"All the 44 elected members of the party have taken a unanimous decision that they would not leave the party under any circumstances and indulge in anti-party activities. We have given a written declaration on stamp papers," senior West Bengal Pradesh Congress leader Abdul Mannan said.

"No one was forced or directed to give the declaration," said Mannan who was elected from Champdani constituency in Hooghly.

"We have seen in the past that many Congress workers left the party after being elected legislator. The declaration is aimed at preventing such desertions. We will go by the party's decision," he said.

A number of legislators who had won on Congress tickets in the previous assembly, later crossed over to the ruling Trinamool Congress.