UDP won 11 seats in the Meghalaya assembly polls and PDF won two seats.
Two major regional parties - the United Democratic Party (UDP) and the People's Democratic Front (PDF) - on Sunday extended their support to the NPP-led alliance, increasing the number of MLAs backing the Conrad K Sangma-led coalition to 45.
The UDP and the PDF are allies of the NPP in the outgoing Meghalaya Democratic Alliance (MDA) government.
The BJP and the HSPDP, with two MLAs each, besides two Independents, have already submitted their letter of support to the NPP, which has won a record 26 seats in the February 27 elections.
"I, on behalf of the parliamentary party of the United Democratic Party, do hereby extend support for government formation," UDP chief and former speaker Metbah Lyngdoh said in the letter submitted to NPP supremo Conrad K Sangma.
PDF MLAs - Banteidor Lyngdoh and Gavin Mylliemngap - also met Sangma at his residence, during the day, and handed over their letter of support to him, party members said.
The UDP has clinched 11 seats in the recently concluded elections, and the PDF two.
A special assembly session has been convened for the oath-taking ceremony of MLAs, scheduled to be held on Monday, and the election of a speaker, to be conducted later in the week.
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