New Delhi: After Nitish Kumar made it clear that the BJP’s Narendra Modi is unacceptable as a candidate for Prime Minister, he has been attacked by the BJP’s parent body, the Rashtriya Swayamsewak Sangh (RSS).  “Will Nitish decide what sort of person makes a good PM?” Mohan Bhagwat of the RSS is reported to have said in Maharashtra.

Mr Kumar partners with the BJP in the government in Bihar.  His Janata Dal (United) is also a member of the NDA, the coalition of opposition parties headed by the BJP.

Yesterday, he said that the BJP must pick its candidate for Prime Minister before and not after the general elections in 2014, so voters know who they are supporting.  He also said this person must have “clean and secular credentials.”   Mr Modi, who is the Chief Minister of Gujarat, nurses prime ministerial ambitions, but is dogged by the communal riots of 2002 in his home state.

The outburst by the RSS leader has raised the pitch of the escalating tension between Mr Modi and the Bihar Chief Minister. “There can be no compromise on secularism, or social justice,” warned Shivanand Tiwari, a leader from Mr Kumar’s party. Then came the warning of a split.  “We won’t compromise on the conditions of the alliance, whether we remain in government or not,” he said.

“Modi is no different from Advani, Vajpayee as far as secularism is concerned,” said BJP leader Balbir Punj today.  However, the BJP in Bihar has stood by Mr Kumar. The Deputy Chief Minister, Sushil Modi, who is from the BJP, said yesterday that he agrees that whoever is picked as the NDA’s choice for prime minister should be acceptable to all “like former PM Atal Bihari Vajpayee.”

Mr Kumar has never been a fan of Mr Modi’s – in recent years, he told the BJP that the Chief Minister of Gujarat could not campaign for their alliance in Bihar for either the general or the state elections.  Mr Modi recently made remarks at a rally about caste politics in Bihar.  Mr Kumar retorted that he did not need sermons.