Buoyed by NDA constituents' win in seven of the 12 bypolls whose results were declared on Tuesday, BJP claimed people have shown their preference for its developmental politics over "vote-bank politics" of Congress and Samajwadi Party.
The party's national secretary Shrikant Sharma used the UP bypoll results to target the Akhilesh Yadav government, alleging it had "failed" on all fronts and people had voted against it.
All the three seats that went to polls were earlier held by SP but it could retain only one with Congress and BJP winning a seat each.
BJP also won the Ghaziabad mayoral elections.
"By misusing the official machinery and deploying its goons, SP had managed to win in local polls so far. People have given it a stern message now.
"A countdown to its government has begun. It has failed on all fronts. Corruption and crime are at a high while public facilities like education and health are in a disarray," Sharma charged.
UP goes to Assembly polls early next year.
BJP won two out of three seats in Congress-ruled Karnataka and presented the result as people's "disapproval" of the state government which, Sharma alleged, was "neck-deep" in corruption.
Its allies Shiv Sena, Akali Dal and RLSP also won a seat each in Maharashtra, Punjab and Bihar respectively.