The three secretaries wrote to Tharoor conveying their unavailability to depose before the panel at its meeting on July 28.
Tharoor said that no constituted procedure was followed in introducing the motion that requires the Speaker to get the leave of the House before it can be introduced.
Dubey, in a tweet on Wednesday tagged TMC supremo and West Bengal Chief Minister Mamata Banerjee, and alleged that MP Mahua Moitra's comments show her party's attitude.
Dubey raised the issue in the Lok Sabha, saying a letter has already been submitted to the Speaker in this regard on Tuesday.
Well within Parliament panel's mandate to seek clarification from Centre on 'manipulated media' issue: Tharoor
Centre wrote "a strong communication" to Twitter registering objection to the use of 'manipulated media' tag on certain tweets, according to sources.
The MLA of Jamtara, along with his companions, entered the sanctum sanctorum of the temple and performed the puja.