“It will be a tough battle for the party,” Karat said at “Meet the Press” programme organised by the Kolkata Press Club.

“There are some other factors, barring the unity of the Opposition parties,” Karat added but did not elaborate on this.

This is not the first time that a senior leader of the party has rung the alarm bell. Earlier, it was party patriarch Jyoti Basu who had said that the Left would lose some seats to the Opposition. While Basu — a known election strategist for the party — had said a month ago that the coming together of Congress and Trinamool would pose difficulty for the party, Karat hinted at “some other reasons”. The CPM general secretary, however, did not clarify in detail the “fear factors”.

In the run-up to the Lok Sabha polls, party state committee has asked all its district committees to submit a detailed report about its position at the grassroots level.

Most of the 19 district committees have already filed their report. According to the report, the party would face neck-to-neck fight even in rural constituencies considered as party stronghold.

Sources said these reports gave an impression that the Opposition is successfully exploiting the Left Front government’s controversial land acquisition policy for industries.

Moreover, factionalism in party ranks and dent in its Muslim votebank by Trinamool Congress chief Mamata Banerjee are also a serious concern for the party, said the sources.

With the party on a backfoot when it comes to state issues, the CPM is making all out effort to shift the focus of the campaign to national issues. The top brass at Alimuddin Street party headquarters has issued instructions to all its ranks to put forward issues like economic crisis and failures of the UPA government.

In an effort to win back Muslim support, which the party lost considerably to Trinamool after Nandigram and Singur fiasco, the CPM has begun campaigning against Mamata Banerjee’s proximity to the BJP.

“In the Trinamool manifesto we did not find a single word against the BJP,” said Karat.