The Central Bureau of Investigation on Sunday asked Uttarakhand Chief Minister Harish Rawat to appear before the agency on May 24 in connection with a probe into the sting operation involving him.
Rawat has been asked to appear on Tuesday, official sources said.
The CBI had last week rejected the Uttarakhand government's notification withdrawing the case related to the sting operation.
The agency had said the notification was rejected after taking legal opinion, which said there was no ground for its withdrawal and it was "not legally tenable".
Meanwhile, Harish Rawat said that he will fully cooperate with the CBI.
"I will fully cooperate with the agency (CBI)," Rawat said.
The chief minister said he had earlier requested the CBI to come to Dehradun to question him as it would be difficult for him to go to Delhi to appear before them but they rejected his request.
The CBI will continue its preliminary inquiry into the episode that allegedly involved horse trading attempts to save the Rawat government.
The CBI had registered a preliminary enquiry on April 29 to probe the "sting operation" purportedly showing Rawat offering bribes to rebel Congress lawmakers to support him during a floor test in the Uttarakhand assembly.
The agency had summoned Rawat for examination for May 9 but he had sought more time after which he won the floor test and returned to power.
Rawat has denied the allegation and called the video fake after it was released by the rebel Congress legislators but later admitted that he was on camera in the sting operation.
After Rawat's victory in the floor test, the state cabinet met on May 15 and withdrew the notification recommending a CBI probe into a sting operation involving him.
Instead, the state cabinet decided to constitute a apecial investigating team to probe the case as it was a state subject.
The case was handed over to the CBI when President's rule was imposed in the state.
The notification was withdrawn immediately after Rawat proved his majority in the assembly and his government was restored.
The chief minister had failed to get a reprieve from Uttarakhand high court also which had refused to quash the ongoing CBI probe into the sting operation.
On May 20, Justice Sarvesh Kumar Gupta of the Uttarakhand high court had said quashing the CBI probe into the sting CD at this stage was not possible.
