Bahuguna, who is in New Delhi, handed over his resignation to Lok Sabha Speaker Meera Kumar, the statement said.
The resignation came after Bahuguna was elected to the state assembly from Sitarganj assembly seat on July 11.
Bahuguna has already said the candidate for the Tehri constituency will be finalized by August 15.
The party high command is likely to hold discussions with the leaders of the state Congress party to build a consensus over the candidate.
Speculation is rife that Bahuguna is keen to field wife Sudha from Tehri.