The Trinamool Congress' decision to withdraw from the UPA appears a logical climax of the constant friction between Mamata Banerjee's party and the Congress over a large range of issues spanning diplomatic, economic and political matters.
The two parties came together in 2009 ahead of the Lok Sabha polls, but then too there was a tussle over the number and nature of seats to the Congress. Banerjee won the battle.
After the United Progressive Alliance's (UPA) victory, Banerjee took over as railway minister, while five of her colleagues were sworn in as ministers of state.
Relations again soured in the 2010 Kolkata civic polls as the Congress - unhappy with the number of seats given to it - fought alone, and suffered a humiliating defeat. The Trinamool won an overwhelming majority.
Before the West Bengal assembly polls last year, there was again a prolonged stand-off over the number of seats for the Congres, but yet again its leadership blinked and the party got to fight only 65 seats in the 294-seat assembly.
After the assembly polls, the two parties formed an alliance government in the state. Soon the troubles escalated, with the Congress ministers complaining of being kept in the dark about major decisions.
The first revolt came earlier this year, when Congress minister Manoj Chakraborty resigned calling Banerjee a "dictator".
The relations deteriorated with each passing day, with Banerjee even once asking the Congress ministers to "leave, if you want to".
Banerjee's battles with the central government continued, as the Trinamool sought a three year moratorium on interest repayments for loans to tide over the debt-ridden state's financial problems.
Trinamool also confronted the Congress over the Teesta treaty with Bangladesh and repeated petro price hikes.
Last September, the UPA government suffered a major diplomatic embarrassment as Banerjee cancelled her trip to Dhaka along with the prime minister saying the Teesta treaty was against the interests of north Bengal. A red prime minister returned from Bangladesh without signing the pact.
Later, Banerjee forced the central government to go back on its decision to allow 51 percent Foreign Direct Investment in retail.
There was another major stand-off after an angry Banerjee forced her party leader and Railway minister Dinesh Trivedi to resign after he raised train fares. Banerjee's long time associate Mukul Roy became minister and withdrew most of the hikes.
The Congress finally checkmated her in the presidential elections in July. After opposing Congress nominee Pranab Mukherjee for days, and trying to put up her own candidates, Banerjee had to finally extend support to him.
The final act in the battle came last week when the suddenly emboldened UPA government raised diesel prices by Rs 5 a litre and cut down on the number of subsidised cylinders per household to six. A day later, it announced a series of sweeping reform measures, including allowing FDI in retail.
An angry Banerjee gave a 72-hour deadline for a roll back, otherwise "hard decisions" would be taken. The Congress refused to relent, and Banerjee responded by withdrawing support Tuesday.