The West Bengal based Irinamool Congress and the Congress will fight the Lok Sabha election together against the state's ruling Left Front, leaders of the two parties said in Kolkata on Sunday night.

"We have decided to fight the elections together," state Congress president Pranab Mukherjee said at a joint

media conference with Trinamool Congress chief Mamata Banerjee late in the night after a 70-minute meeting.

However, the two leaders said the final contours of the alliance including the number of seats to be contested by each party will be decided in the coming days after further talks.

"We had good and useful discussions. But as we have some compulsions, we will

very soon tell you the final outcome of the talks," Congress Working Committee member and External Affairs Minister Pranab Mukherjee said at the brief media meet.

Asked whether it was an alliance or a seat adjustment, Mukherjee said: 'That's upto you to say."

On how many of the state's 42 seats each party could fight, he said: "Finally when we announce you will get the numbers."