The DMK’s decision to quit the government has shrunk the comfort zone of the Congress-led UPA in the Lok Sabha though it still has support beyond the half-way mark.
The major constituents of the UPA including the Congress (203), Nationalist Congress Party (9), Rashtriya Lok Dal (5) and National Conference (3) add up to 220 members in the 545-member Lok Sabha.
With the DMK (18), this number was 238.
The UPA also has the outside support of the Samajwadi Party (22), Bahujan Samaj Party (21), Janata Dal-Secular (3) and Rashtriya Janata Dal (3) -- a total of 49 members.
Political sources said the UPA also has the support of at least eight members from smaller groups and independents, taking its total support in the Lok Sabha beyond the half-way mark of 271.
There are four vacancies in the Lok Sabha.
The Trinamool Congress withdrew support to the UPA last year over the move to allow FDI in multi-brand retail and other decisions.
The DMK Tuesday quit the UPA government voicing dismay over India's stand over Sri Lanka at the UN Human Rights Council.