The former three times chief minister (1979-94) was reinstated as SSP president at a ceremony at the Sangram Bhavan here.
In 2003, Bhandari had left the SSP and joined the SPCC as its president, a post that he held till April 20 this year when he was removed by the Congress high command.
"Since SSP's main agenda is to change the government, we will find and use all means to make this party strong with the backing of the people," Bhandari said on the occasion.
He said that the SSP merged with the Congress in 2003 to give the people a voice at the Centre, but the party failed to deliver and expose corruption in the state.
"The Congress party's divide and rule policy was evident in the way it was functioning which is why there was only one way to bring about change," Bhandari said.
Rajendra Upreti, who had taken over as president after the departure of Bhandari to Congress was made the working President and another loyalist, Kamal Rai, the SSP Vice President.