West Bengal Chief Minister Mamata Banerjee is due to meet Congress chief Sonia Gandhi in the national capital on Tuesday.

While the main purpose of Trinamool chief’ meeting with Congress president is the upcoming presidential elections, the two leaders are also likely to discuss the formation of an anti-BJP coalition to counter Narendra Modi-led NDA in the 2019 Lok Sabha elections.

Congress chief has taken the lead to identify a candidate who is equally acceptable to all the opposition parties.

Sonia and her son Rahul had held deliberations with senior leaders of opposition parties to build consensus on a unanimously accepted candidate.

Last week, when she was hospitalised following complaints of food poisoning, the 70-year-old Congress chief had called Banerjee.Since President Pranab Mukherjee’ term will expire in July, Gandhi had already met Janata Dal-United leader Nitish Kumar and NCP chief Sharad Pawar over the issue.

Meanwhile, Rahul Gandhi has deliberated with the Left’ Sitaram Yechury and Samajwadi leader Akhilesh Yadav.Interestingly, in the garb of selecting an acceptable candidate, the Congress-led Opposition is also seen as moving to engineer a coalition of non-BJP parties for 2019, when Prime Minister Narendra Modi seeks a second term.

But the coming together of Congress and TMC at the Centre is likely to create problems as Sonia Gandhi’ party is in alliance with the Left in West Bengal and had unsuccessfully contested the last assembly elections against Mamata’ party.

But the new political alignment is creating discomfort in Kolkata, where the Congress is an ally of the arch-enemy of the state’ ruling Trinamool Congress, the Left Front. The two parties are trying to play down the impression that while they are shaking hands in Bengal, the Congress and the Trinamool seem to be drawing closer in Delhi.

West Bengal Congress unit chief Adhir Choudhury has reportedly written to Sonia Gandhi, warning that a discussion of anything but presidential polls with `Banerjee could injure the Congress in the state.