Party sources here said the TMC MPs are likely to take their oath in early June.
Banerjee had earlier stated that party MPs would leave for Delhi on May 24 and take oath on May 25 and 26.
Deferment of the oath taking of TMC MPs has fuelled speculation about the party's participation in the swearing-in of Narendra Modi as Prime Minister on May 26.
TMC leadership is tightlipped as to whether the party would attend Modi's swearing-in ceremony.
There had been war of words between Mamata Banerjee and Narendra Modi during the election campaign.
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