With the MDMK declaring on Wednesday that its four MPs will not back Prime Minister Manmohan Singh's government, floor managers of the ruling coalition floor managers are struggling to stack the numbers to prove its majority in the Lok Sabha.
MDMK chief Vaiko told a television channel over telephone from the US that he and his MPs would not support the Congress-led United Progressive Alliance (UPA) in the event of a floor test.
The declaration made the numbers game that much more trickier for the UPA, which has 226 MPs without the support of the Samajwadi Party and its 39 MPs.
Even if all the 39 MPs were to support the UPA in case of a trust vote, the government would have 265 votes -- seven short of the magic halfway figure of 272.
But two of the Samajwadi Party MPs have declared that they will defy the party whip and vote against the government.
The Congress is banking on the smaller parties, some of which are yet to made up their mind or are in a dilemma.
They include the Trinamool Congress (1), Janata Dal-Secular (3), All India Majlis-e-ittehadul Muslimmen (1) and Indian Union Muslim League (1).
Apart from the Congress' 153 MPs, the UPA has Rashtriya Janata Dal (24), DMK (16), Nationalist Congress Party (11), PMK (6), Jharkhand Mukti Morcha (5), Lok Janshakti Party (4) and some smaller parties.
Of the six independents, Babulal Marandi - who is now in the Jharkhand Vikas Morcha - and Kerala's Sebastian Paul will vote against the government.
The votes of SK Bwiswmuthiary, who told IANS that he had not made up his mind, Mani Charenamai, Thupstan Chhewang and Harish Nagpal are unclear.
While the Jammu and Kashmir National Conference (2 MPs) announced that it was not against the nuclear deal, the three-member Telangana Rashtra Samiti said it would not mind supporting the government in a possible floor test if the government announced the creation of separate Telangana state.
Unfortunately for the UPA, the Samajwadi Party is believed to be divided over supporting the contentious India-US nuclear deal.
According to party insiders, some MPs who cited illness for their absence at the meeting Tuesday have already begun hobnobbing with the Bahujan Samaj Party (BSP).
"After the delimitation exercise (which will see a new electoral map in the next election), some Samajwadi Party MPs are not sure of winning their seats on party ticket," said a party leader.
Notwithstanding the obstacles, the government seemed confident of winning a floor test.
"We are sure that we can prove majority in the Lok Sabha. We are working on it. We will prove it as the president directs us," a confident Parliamentary Affairs Minister Vayalar Ravi, one of the trouble shooters of the government in this crisis, told IANS.