They have been trying to conceal the crack all these years but it is slowly beginning to surface.
If the scene at Prime Minister Manmohan Singh's dinner party is any indication, the Congress party is ready to dump Trinamool Congress chief and West Bengal chief minister Mamata Banerjee and join hands with Samajwadi Party (SP).
Interestingly, SP Chief Mulayam Singh Yadav, whose party is not an ally of UPA, attended the dinner party hosted by Manmohan Singh to celebrate UPA-II's completion of three years in power.
The event was meant only for close allies of the Congress party but the SP chief was seen sharing the dais with the Prime Minister during the release of the government's annual report card. He was also spotted sitting next to the Congress party President Sonia Gandhi at the dinner.
On the other hand, Mamata Banerjee, whose party is an ally in the UPA government, didn't attend the dinner party. Dravida Munnetra Kazhagam (DMK) supremo M Karunanidhi too skipped the party.
It may be worth mentioning that all is not well between the Congress and Mamata Banerjee. And skipping the dinner was just a tip of the iceberg.
The TMC, which has 25 MPs in Parliament, had gone against many policy decisions of the Congress in the past. In fact, Mamata is sort of a stumbling block to reforms proposed by the Congress.
The TMC openly criticized the Congress when the petrol price was hiked last year. It opposed the move of the government to allow foreign direct investment (FDI) in retail sector, which was meant to boost the country's economic growth.
Mamata also opposed the government's anti terrorism proposal National Counter Terrorism Centre (NCTC). She then replaced Dinesh Trivedi with Mukul Roy as the Railway Minister after the former hiked rail passengers' fare in the annual railway budget.
As if to test the patience of the Congress party, Mamata recently gave 15 days ultimatum to the UPA government to fulfill her demand for a financial package for West Bengal.
Looking at the way Mamata has been going against the policy decisions of the government, it is not surprising that the Congress party is getting close to SP as it will make a good substitute in case TMC leaves UPA.
The Congress had earlier sent Parliamentary Affairs Minister Pawan Kumar Bansal and senior party leader Motilal Vora to the swearing-in ceremony of UP Chief Minister Akhilesh Yadav, son of SP chief Mulayam. Congress party president Sonia Gandhi too sent letters to Mulayam and his son Akhilesh, wishing them and expressing her regret for not attending the function.
Maybe the Congress party has had enough of Mamata and ready to dump her if she flexes her muscle again in the future. After all, SP is close to the Congress like never before.