Describing as "immoral" the proposed tie - up with the CPI - M - led Left Front for the West Bengal assembly polls, a Congress lawmaker on Sunday called for the central leadership's intervention.
Opposing any electoral arrangement with the Left, Alipurduar lawmaker Deba Prasad Roy threatened not to contest or take part in the poll campaign.
"I don't think I am ready to contest the polls when efforts are being made to notch up this immoral and unprincipled tie - up with the Left Front. In case such an arrangement happens, I will neither contest nor participate in any way, in the polls including campaigning for the party.
"I have already informed about my decision in clear terms to party president Sonia Gandhi. I call upon the people in the party to follow their conscience and sincerely hope the central leadership will take a suitable decision on this tricky issue, " he said.
While a large section of the state Congress and the Left Front spearhead Communist Party of India - Marxist have been rooting for a tie - up, there has aso been opposition on the issue from both the camps.
Recently Front constituent Revolutionary Socialist Party (RSP) had threatened to walk out of the coalition alleging the "unilateral decision" of the proposed electoral arrangement was being imposed on it.
Roy's comments came on day when state Congress president Adhir Ranjan Chowdhury asserted the tie - up was on track.
"Talks are on and the tie - up is on track. The Congress will soon come out with the candidates list, " he said.