"Congress is no longer what it used to be, it is living in denial," Mr Scindia said after his induction into the BJP, wearing the party's saffron silk scarf. He also heaped praise on PM Modi, saying "the country is safe in his hands".

The 49-year-old has been named for the Rajya Sabha, which is seen to be a precursor to a spot in PM Modi's cabinet. Mr Scindia reportedly asked for the initial joining time of noon shifted by two hours to avoid "Rahu Kaal".

He is expected to fly back to Madhya Pradesh soon to lead efforts to topple the Congress government. The Congress has 120 MLAs in Madhya Pradesh, four more than the majority mark of 116 in the 230-member assembly. If the 21 resignations are accepted, the majority mark will fall to 104. This will make it easier for the BJP - with 107 MLAs - to stake claim to power.

Both the BJP and the Congress moved their MLAs out of Madhya Pradesh to guard their flock ahead of any test of strength in the assembly. The BJP has put up its MLAs at the five-star ITC Grand Bharat in Gurgaon, while the Congress on Wednesday flew its members to Jaipur in Rajasthan, where the party is in power.

The Congress moved 94 MLAs to Jaipur. The party claims 19 MLAs loyal to Mr Scindia, still in Bengaluru, will not join the BJP. Chief Minister Kamal Nath said last night: "There is nothing to worry about. We will prove our majority."

One of the rebels said this morning: "We came for Maharaj... not to join the BJP." The Congress's troubleshooter in Karnataka, DK Shivakumar, told NDTV that he was confident most of the MLAs would return.

Mr Scindia's switch to the BJP, a party he criticized just days ago over the Delhi violence, comes as a jolt to the Congress, which has been struggling with disenchantment within the ranks and a perceived leadership vacuum. The four-time Lok Sabha MP from Guna had been stewing for months over what he saw as his sliding stock in the Congress. His supporters say the Gandhis did not make any attempt to reach out to him.

Once close to the Gandhi family, Mr Scindia lost the race for chief ministership in 2018 after he showed support of only 23 MLAs despite making a sizeable contribution to the Congress' unexpected Assembly polls win.

In August, he was one of a few opposition leaders who supported the centre's Article 370 move to end special status to Jammu and Kashmir.