Sachin Pilot is Deputy Chief Minister in the Rajasthan government. (File photo)
A letter asking Rajasthan Deputy Chief Minister Sachin Pilot to appear for questioning in an investigation into alleged attempts to destabilize the state government is believed to have pushed the Congress crisis to breaking point.
Sachin Pilot was on Friday summoned by the Rajasthan anti-terror squad and the Special Operations Group to appear for questioning in an investigation that began during the Rajya Sabha election in June, when allegations of poaching of Congress MLAs emerged in the contest for three seats.
Chief Minister Ashok Gehlot, as state home minister, is in charge of the Special Operations Group, so the letter was seen as an affront by his deputy. That Ashok Gehlot has also received a similar summons for questioning is viewed as a cover for the humiliation served to Sachin Pilot, say sources close to him.

Sachin Pilot was on Friday summoned by the Rajasthan anti-terror squad and the Special Operations Group.
"Never before has a sitting state president been served such a letter," said sources close to Sachin Pilot, calling the investigation an excuse to harass and monitor the Deputy Chief Minister.
"No one is above the law, be it the Prime Minister or Chief Minister, when it comes to matters like this. We will cooperate fully with the investigation," said Ashok Gehlot on the summons.
The investigations are based on tapped phone conversations of two BJP leaders in the days leading up to the Rajya Sabha election, which raised allegations of a move to topple the Congress government by luring MLAs to the BJP.
The Chief Minister accused the BJP of offering Rs 15 crore to Congress MLAs to switch sides, in order to set up a coup on the lines of Madhya Pradesh, where the Congress government crashed after senior leader Jyotiraditya Scindia quit, taking 22 MLAs with him.
When the Congress won two of the three Rajya Sabha seats, Sachin Pilot had said reports of his party MLAs being lured were "baseless". He also emphatically denied reports that he was also in talks with the BJP.
Sources say Sachin Pilot was furious when he received the notice for questioning.
Sachin Pilot then stormed off to Delhi with MLAs loyal to him.
Both Sonia and Rahul Gandhi have been briefed about the situation.
Sources say the Congress leadership is also upset about the summons to Sachin Pilot, which precipitated a huge crisis in Rajasthan when it has already lost two big states to the BJP.
"Sonia Gandhi will take a call on the matter and all must work together whatever the differences," a party insider said. Chief Minister Ashok Gehlot said yesterday that the BJP is trying to grab power in the state by bribing MLAs the way they did in Madhya Pradesh. The Anti-Corruption Branch is questioning three Independent MLAs who allegedly made offers of money, sources said.