Calcutta, Oct. 30: An attempt to push up the BJP's vote share so that the Opposition remains divided and the minority community retains its loyalty towards Trinamul - these two objectives are perceived to be the reasons behind Mamata Banerjee's recent attacks on the BJP, sources in Bengal's ruling party said.

In a departure from her silence on the BJP in the last few months, the chief minister has started attacking the party since last Sunday. The sudden shift of gear surprised some in Trinamul, too, the sources said.

Some Trinamul leaders told The Telegraph that given the decline in the BJP's support base - from a 17 per cent vote share in the 2014 Lok Sabha polls to only 9 per cent in the civic polls in April - they were taken aback when the chief minister targeted Modi's party.

'At a time we were preparing for a battle with the Left, Didi launched an attack on the BJP, which has become almost irrelevant in Bengal. This was unexpected,' a Trinamul MLA said.

Trinamul insiders said that the possibility of a further slump in the BJP's vote share is not ruled out since the party bagged 18.5 per cent in Asansol, 8.6 per cent in Bidhannagar and 6.4 per cent votes in Bally in the October 3 elections.

From making a direct appeal to Bihar voters to choose the Nitish Kumar-led grand alliance, to launching an attack on the 'divisive politics' by the BJP-led government at the Centre, Mamata has upped the ante.

Some Trinamul MLAs expressed fear that Mamata's belligerence might end up benefiting the BJP as the party would get the status of an important Opposition party.

But other Trinamul leaders said the BJP-bashing strategy might be part of her overall plan of dividing the Opposition space so that Trinamul does not face any stiff challenge in the Assembly polls.

'The vote distribution of the 2014 Lok Sabha polls suits our party the most and she would try her best to ensure that the parties in the Opposition fight it out among themselves while our vote share remains intact,' said a veteran Trinamul leader.

Although, there was a spike in the BJP's share of votes in the 2014 Lok Sabha polls, Trinamul's hegemony in Bengal was undisputed as it bagged 34 seats, with a vote share of 39.02 per cent.

Recent elections have revealed that the BJP has failed to grow its base and even in urban areas of Calcutta, Bidhannagar and Asansol, the party has lost ground while the Left parties have upped their share.

With the possibility of the 2016 Bengal elections becoming a referendum on five years of Trinamul rule, Mamata would have reasons to worry if the polls became a two-way battle between Trinamul and the Left.

'She is probably trying to avoid that situation and trying to ensure that the BJP also improves its share,' said a source.

A strategy like this will have some collateral advantages for Mamata as the BJP-bashing in the middle of the beef controversy could endear her to the minority community, who voted Trinamul in recent years.