The left parties on Tuesday said that it was too "premature" to even discuss who would head a united Opposition in the 2019 lok Sabha polls, after the Trinamool Congress argued that a leader with "impeccable credentials" should lead the charge against the BJP.

Days before a crucial Opposition meet on February 1, a TMC leader, on condition of anonymity, said they felt that even though every Opposition party would like their party chief to lead the Opposition camp, the prospective leader "must have the experience of being the Chief Minister of a State and Union Minister".

Reacting to the remarks, the left parties said the TMC was just falling short of naming its party Chief Mamata Banerjee as the Prime Ministerial candidate by putting these criteria.

"If the TMC feel that these criteria should be followed, they should also take the name of the person who they think meets these criteria. We have not yet reached that stage and we are not discussing the elections. Of coarse, elections are there, but it is for the parties to discuss what kind of electoral tactical lines they will adopt.

It is premature," CPI leader D Raja told PTI.

The left leader felt that in current situation all secular and democratic parties should come together and "resist the onslaught that is coming from the BJP-RSS".

Earlier in the day, Trinamool Congress leader Derek O'Brien said, "It is only natural that someone with impeccable credentials should play a lead role in 2019."

As the opposition is gearing up to put up a united fight against the Narendra Modi dispensation, the race to name its leader has also begun.