"In Delhi, Trinamool Congress is helping BJP to pass Bills. But, at the same time, they are fighting in the state. This is a strange understanding and we are unable to explain it," Bose told a press conference here.
On Trinamool Congress supremo and state Chief Minister Mamata Banerjee meeting Gorkha Janmukti Morcha (GJM) leaders charge-sheeted by CBI, Bose said he was not surprised.
"When Transport Minister Madan Mitra was arrested by CBI (in connection with the Saradha chit fund case), she took to the streets to agitate. So, this is not at all surprising," said Bose, who is also the Left Front chairman.
Banerjee met Gurung and other leaders in Darjeeling two days ago.
Responding to a question, he said that the Trinamool Congress government had failed to bring any investment to the state.
However, Bose welcomed the opening of a 'Biswa Bangla' store at Bagdogra airport earlier in the day by Banerjee.