Mumbai: Ahead of the crucial meeting of Shiv Sena (UBT) MPs in New Delhi amid heightened speculation of rebellion, party leader Arvind Sawant on Thursday said action will be taken against those who violate the whip.Sena (UBT) Rajya Sabha member Sanjay Raut said a "lesson needs to be taught" to the rebels.Also read: 25-26 MPs of Samajwadi Party ready to break away, says Keshav Prasad Maurya amid OP Rajbhar's split claimsAmid the escalating crisis, a group of rebel Shiv Sena (UBT) leaders is learnt to have met Lok Sabha Speaker Om Birla informally on Wednesday, claiming the support of six of the party's nine MPs in the Lower House, according to sources.In a swift counter-offensive to contain the damage, the party high command issued a mandatory three-line whip, summoning an emergency parliamentary party meeting in New Delhi on Thursday to force a showdown where the MPs will have to mark their presence physically.Speaking to reporters in Delhi, Raut said the whip was issued because there was a need to discuss important issues.The whip has reached all MPs. It has been sent to their homes, emailed, and also sent on WhatsApp, he added."Action will be taken against those who violate the whip, after consulting the party chief (Uddhav Thackeray)," Sawant said.Also read: As Shiv Sena, TMC splits swell NDA ranks, TDP and JDU lose some of their bargaining chipRaut said Thackeray and NCP (SP) president Sharad Pawar called him, during which it was discussed that those who resorted to treachery should not be spared, and to create 'rada' (ruckus) in the constituencies of MPs who ditch the party.The Sena (UBT) leader further said Pawar told him that he will go and address rallies in the constituencies of those MPs.A lesson needs to be taught to these MPs, the Rajya Sabha member said.Sawant said late Shiv Sena founder Bal Thackeray had even suggested beating up MPs, MLAs who switch sides.