Janata Dal (United) president Nitish Kumar on Saturday authorised the party's Jharkhand unit to take all the decisions related to the Assembly election due to be held by the end of this year.
Mr Kumar, also the Bihar chief minister, asked the party workers to take a pledge to address the problems of Jharkhand where his party, an NDA (National Democratic Alliance) ally, would go it alone in the Assembly poll.
Jharkhand is currently ruled by a BJP-led government.
"You will take all the decisions (regarding the assembly polls) and all the leaders would throw their weight behind you," he said at a party meeting at Ranchi.
Mr Kumar said the people of undivided Bihar had been worried when its mineral-rich Jharkhand was carved out 19 years ago, but his government had taken a pledge to bring the state on the path of development and fulfilled it.
"If you work to fulfil your pledges, you will get the support of the people," he said, adding that there should be no compromise on corruption, crime and communalism.
Mr Kumar said the "achievements" of his government in Bihar included round-the-clock electricity, growth in agriculture, 50 per cent reservation for women in local body elections and ban on liquor.
"We not only constructed quality roads, but also made budgetary provision for their maintenance," he said.
JDU vice-president Prashant Kishor said it is surprising that the party could not become strong in Jharkhand despite Nitish Kumar's good governance in neighbouring Bihar for 14 years.
Mr Kishor said he thinks that if 50 to 100 committed party workers make a concerted effort, the JDU would be strengthened in Jharkhand.
"I will do whatever the party tells me. But 100 Prasant Kishors or 100 Nitish Kumars cannot win in just one or two months till you realise to work with a pledge," he told the party workers.
Meanwhile, a BJP minister in Nitish Kumar's cabinet said in Patna that the party's alliance with the JDU is confined only to Bihar and the two parties are free to contest polls anywhere and there is nothing wrong in it.
He, however, claimed that the BJP will win 65 out of the 81 seats of Jharkhand assembly.