Barely half an hour before the trust vote in the assembly, Meghalaya Chief Minister D D Lapang resigned on Wednesday, saying his Congress-led Meghalaya United Alliance government has failed to secure a majority in the 60-member House.

Lapang, sworn in on March 10 after the Congress emerged as the single largest party, submitted his resignation to Governor S S Sidhu, Raj Bhavan sources said.

Speaking to reporters after a Congress Legislature Party meeting, Lapang, who has the support of 28 members, including two Independents, said "Congress could not garner requisite support. So the Congress Legislature Party decided that I should resign."

Nationalist Congress Party leader and architect of the rival Meghalaya Progressive Alliance P A Sangma said the MPA would meet and then stake claim to form the government. The swearing in was likely to be held in the evening.

The chief ministerial candidate of the MPA is United Democratic Party President Donkupar Roy.

Lapang was asked by the governor to prove majority within 10 days.

The CLP had met on Tuesday evening, but a decision on facing the trust vote was postponed till Wednesday morning before the assembly session began.

Earlier, an indication that the Lapang ministry did not have the numbers came when it postponed the speaker's election on the floor of the House on March 17.

The MPA, which has the support of 31 legislators, had earlier moved the Supreme Court after Lapang was invited to form the government, but the apex court declined to intervene.

The MPA comprises 14 MLAs of NCP, 11 of United Democratic Party, two from Hills State People's Democratic Party, one each from the Bharatiya Janata Party and Khun Hynniewtrep National Awakening Movement, besides two Independents.