Named the opposition leader of Bihar, Tejashwi Yadav is spearheading the agitation against Mr Kumar, his former boss, who ended the Grand Alliance with Lalu Yadav and the Congress three weeks ago and formed a new government in Bihar with the BJP.
Yadav today congratulated Patel for his nail-biting finish in the Rajya Sabha election. "Wish you all success in your career", Yadav tweeted.
Yadav also posted a photograph of his with Patel, the political secretary to Congress president Sonia Gandhi, on the microblogging website.
Sharad Yadav backs party's Gujarat MLA Chhotu Vasava who voted for Ahmed Patel. His congratulatory message to Patel assumes significance at a time when the JD (U) has joined hands with the BJP to form the government in Bihar.
The JD-U has removed its Gujarat chief Arun Shrivastav from the post of party general secretary for his "unauthorisedly" writing to the Returning Officer of Gujarat Assembly appointing an election agent for the crucial Rajya Sabha election.
This is the first joint meeting of the Opposition parties after JD (U) broke ranks with them.
The strained ties within the JD (U) were evident on Tuesday after senior leader Sharad Yadav sided with the Opposition in Parliament over the "different sizes" of Rs 500 notes printed by the government after demonetisation.
However, the Grand Alliance government did not last for long as the Bihar Chief Minister Nitish Kumar chose to leave his alliance partners recently after the family members of Lalu Prasad Yadav, the chief of the RJD and father of Tejashwi and Tej Pratap, were accused of being involved in several corruption cases. Yadav had come out against Kumar's decision to ally with the BJP.
On 11 August, he is scheduled to visit the Muzaffarpur-Darbhanga-Madhubani stretch and on 12 August, he is scheduled to go to Madhubani-Supual-Madhepura.