Bharti, who left the BJP accusing Advani of partisan behaviour, has addressed the letter to the former deputy Prime Minister, but has sent it to party president Rajnath Singh.

"In this election, I will not create any hurdle in your becoming the prime minister. In fact, we will support you," she said in the letter which she has signed as putrivat (daughter like).

However, she has ruled out her return to the BJP. "I have not made any decision about joining the BJP or merging my party with BJP. In return (of support), I neither want any seat in the Lok Sabha polls nor do I want to reach any understanding," Bharti said.

The contents of the letter found a mention in the party's central election committee which met on Tuesday. Though, sources close to Bharti refused to comment on whether she would campaign for BJP, in her letter, she said "I extend my full support to you for the post of prime minister of this country and in this regard, I am duty-bound to follow all your directives."

Rajnath Singh has welcomed the letter which comes at a time when senior BJP leader Arun Jaitley [Images] has been protesting appointments made by the BJP chief.