Organising a press conference at the International Convention Center, New Baneshwor, on Saturday, they stressed the need of establishing multiple-identity-based provinces (Koch-Birat, Mithila, Bhojpuriya-Simraungadh, Awadhi-Lumbini and Tharuhat) in the Terai-Madhes.
They said that they were committed to the concept of Autonomous Terai-Madhes Province signed by the party's former President the late Girija Prasad Koirala.
Speaking at the programme organised prior to the Legislature-Parliament meeting, lawmaker and party central member Mohammed Aftab Alam said the concept of five provinces would address the identity and cultural diversities in the Terai Madhes.
Besides, the Congress lawmakers has stressed that the new constitution should address the voices of women, Muslims, Dalits, indigenous nationalities, backward communities and the marginalized groups and be promulgated within May 27.
Some 41 lawmakers from the Terai-Madhes have expressed solidarity to the concept of five provinces, it is learnt.