New Delhi/Mumbai,  Exactly a month after a rebellion among 40 Shiv Sena MLAs on June 20, 12 party MPs on Tuesday switched over to Chief Minister Eknath Shinde's group, dealing another massive blow to embattled party President Uddhav Thackeray.

The MPs who joined the Shinde camp include Shrikant (Eknath) Shinde, Rahul Shewale, Bhavana Gawali, Hemant Godse, Rajendra Gavit, Sadashiv Lokhande, Hemant Patil, Sanjay Mandlik, Dhairyasheel Mane, Shrirang Barne, Krupal Tumane and Prataprao Jadhav.

Shinde made the announcement in Delhi on Tuesday that 12 Shiv Sena MPs have joined him in the interest of the people, and will work for the progress and development of Maharashtra.

He added that the 12 MPs met Lok Sabha Speaker Om Birla and submitted a letter to this effect as the Shiv Sena Parliamentary Party Group in the Lower House.

"While Rahul Shewale is the new Shiv Sena group leader, Bhavana Gawali is now the chief whip of the party in the Lok Sabha," said Shinde.

The CM also made it clear that the whips issued by Gawali will now be applicable to all the 18 Shiv Sena MPs in the Lok Sabha.

The development came a month after June 20, when a Shinde-led revolt by around 40 Shiv Sena MLAs plus 10 Independents and others brought down the Maha Vikas Aghadi (MVA) government of Shiv Sena-Nationalist Congress Party-Congress headed by then CM Uddhav Thackeray on June 29.

On June 30, Shinde was sworn-in as the Chief Minister, while ally BJP's Devendra Fadnavis took oath as the Deputy CM.

The latest turn of events is considered a massive setback for Thackeray, though the party's chief spokesperson Sanjay Raut had repeatedly trashed the upcoming political churning within the party in the past two days.

After offering allegiance to Shinde, the 12 MPs called on Lok Sabha Speaker Om Birla and submitted a letter with various demands.

One of the MPs, Hemant Godse, told mediapersons that they have requested the Speaker to approve the name of Bhavana Gawali as the new chief whip in Lok Sabha and Rahul Shewale as the new party leader in place of current Shiv Sena party leader Vinayak Raut, who is still with Thackeray.

He added that they urged the Speaker to recognise them as a group and allot the Shiv Sena office in the Parliament House to them.

"The Speaker has assured us that after studying the matter, he will take the necessary steps in the matter," Godse said.

Shinde lauded the 12 MPs for taking a principled stand and adhering to the ideals of Balasaheb Thackeray and Dharmaveer Anand Dighe.

"We fought the elections together (with BJP) in 2019. We have brought back the 'natural alliance' with the BJP and rectified the mistake (of MVA) committed two-and-a-half years ago. That's why we are getting huge public support," Shinde asserted.

Earlier on Tuesday, anticipating the political development, the Maharashtra Police and central forces tightened security at the homes and offices of all the 12 MPs who joined the Shinde group.