The faultlines in the UPA government split wide open today, with the Dravida Munnetra Kazhagam (DMK) top brass in Chennai passing a four-page resolution withdrawing its ministers from the Central government and settling for ?issue-based support? instead.

While DMK watchers feel it is an exercise in brinkmanship by the party (they have done it twice before, once in 2004, over the shipping portfolio, and the other in 2009 over A Raja?s inclusion in the Cabinet), Congress sources say that ?they are prepared for the worst.? It means that the Congress leadership is not as eager as it was in the past to woo its ally.

The immediate provocation for this move was the breakdown in seat sharing talks between the Congress and DMK, with the former insisting on 63 seats and the latter unable to oblige with more than 60. The underlying causes of the split, however, directly pertain to the 2G spectrum scam and AICC general secretary Rahul Gandhi?s desire to go it alone in as many states as possible.

After a stormy meeting between AICC in-charge of Tamil Nadu Ghulam Nabi Azad and Tamil Nadu chief minister M Karunanidhi, the latter gave a hint this was coming. ?We have already promised 60 seats, why do they want 63, and now they want to choose constituencies as well,? Karunanidhi had said.

The Congress appeared to be taking it in its stride. Pranab Mukherjee, who had sealed the original alliance with the DMK in 2004, continued his travel plans to Kolkata, and Azad remained incognito for much of the day.

The Congress? calculation as far as its stand is that as a party they have not much to lose in the Assembly polls. ?Whenever we decide to go alone, we should be prepared to lose an election or two, but that is the price to pay to emerge as a main opposition force,? said a source close to the developments.

The Congress has also been embarrassed by the 2G scam. The investigation into the 2G scam has reached the doorstep of Tamil Nadu?s first political family, with Karunanidhi?s daughter Kanimozhi likely to be questioned next week.

With Assembly polls a month away, the DMK?s alliance with PMK, VCK and KDK in western Tamil Nadu should still cheer DMK, while the Congress feels that a demanding ally should be shown its place.