At least 12 of 19 MPs of Shiv Sena will form a separate group in the Lok Sabha and meet Speaker Om Birla to submit a formal letter, a Shiv Sena MP from Maharashtra claimed on Monday.

The move comes weeks after the Uddhav Thackeray-led Shiv Sena witnessed a vertical split with 40 of the MLAs joining the faction headed by Chief Minister Eknath Shinde.