The meeting will forge a common stance on the demands of the United Democratic Madhesi Front (UDMF), acording to a leader privy to the meeting.
The top leaders from the Nepali Congress, CPN-UML and UCPN (Maoist) are taking part in the meeting.
The leaders said they will address the demands of the UDMF prior to the Legislature-Parliament meeting on Tuesday.
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The three major parties have already agreed to resolve the Madhesi demands including the delineation of the provinces through the formation of a high level political mechanism.
