A day after DMK withdrew support to UPA Government on Sri Lankan Tamil's issue, the party's five Union ministers today submitted their resignation to the Prime Minister amid speculation that DMK Chief M Karunanidhi's son M K Alagiri was unhappy for not being kept in the loop.

Eyebrows were raised as Alagiri and D Napoleon did not go along with other three ministers S S Palanimanickam, S Gandhiselvan and S Jagatrakshakan to submit their resignation to Prime Minister Manmohan Singh at around noon at his Parliament House office.

Alagri along with Napoleon met Singh an hour later to tender their resignation fuelling speculation that he had reservations about how the decision was taken by the party.

The DMK, which formally ended its nine-year-old alliance with the UPA yesterday, has 18 members in the Lok Sabha and six MPs in the Rajya Sabha. The party ruled out supporting UPA from outside or joining the BJP-led NDA.

Alagiri was holding the chemicals and fertilisers portfolio with Cabinet rank. Napoleon, Palani Manickam, Jagatrakshakan and Gandhi Selvan were ministers of state.

"As per the decision taken by Kalaignar Karunanidhi, we have handed over the resignation letter to the Prime Minister," DMK Parliamentary Party leader T R Baalu told reporters.

Asked whether the party will join BJP-led NDA, Baalu, who accompanied three ministers to meet Prime Minister, said, "No...Never". Karunanidhi has ruled out outside support to the UPA Government.

Meanwhile, DMK ally VCK's leader and Lok Sabha MP Thol Thirumavalavan met President Pranab Mukherjee this afternoon and handed over the letter withdrawing support of UPA Government.

"Our government is not supporting the cause of our eelam Tamil (Sri Lankan Tamil). So, I took this decision," he told reporters.

"I have withdrawn the support as the Centre has shown no keenness in condemning the genocide of Tamils in Sri Lanka," Thol said after the meeting Mukherjee.

Baalu had met the President last night to hand over letter of DMK ending its alliance with the UPA.

DMK, which was the second biggest constituent in UPA, quit the UPA in protest against government not taking up its concerns in the proposed UN resolution against Sri Lanka on alleged human rights violations of Tamils there.