In a virtual rebellion against the UPA government, its largest ally Trinamool Congress on Friday threatened to pull out over the petrol price hike, as it sought an appointment with prime minister Manmohan Singh before taking "any vital decision".

"Our withdrawal of support may result in fall of the government. But since the prime minister is away, we want to discuss with him and have sought an appointment with him," Trinamool Congress chairperson Mamata Banerjee told reporters at the state secretariat in Kolkata.

"Discussions are required before a vital decision is to be taken," she said after her party's parliamentary wing submitted a resolution to her calling for pull out from the UPA.

Banerjee, in the first-ever attack on the Congress since the formation of the UPA-II government in 2009, said her party would seek an appointment with the Prime Minister sometime between November 8 and 10 according to his convenience after he returns from abroad.

It was unacceptable that such a crucial decision on petrol price hike had been taken in the absence of the prime minister, she said.

Banerjee said an emergency meeting of the Trinamool Congress parliamentary party was in favour of quitting the UPA for the unilateral decisions of major ally Congress, without consulting allies and keeping them in the dark, she said.

"We have been silenced and not heard in the union cabinet. Our only cabinet minister Dinesh Trivedi, when he raises any issue concerning the people, is told to keep quiet.

We have tolerated so much and adjusted," Banerjee said, adding there was lack of coordination and cooperation in the UPA.

Pointing out that Congress was dependant on support of allies like the Trinamool Congress, NCP and DMK to run the UPA government, she said, "But we are not dependant on Congress."

"They (Congress) may be a big party, and we may be smaller parties. But they do not have the majority of their own at the centre. They are dependant on the support of the allies for survival," Banerjee said.

While maintaining that she was not trying to blackmail the government, the Trinamool chief said the rise in fuel prices so frequently was "unacceptable".

"We want the government to run for five years. We follow the coalition dharma. This was our commitment when the government was formed. We are not trying to blackmail the government. In West Bengal, we are in power with two-thirds majority and we are not dependant on Congress to run the government. We can run the government in this state on our own even if Congress is not with us, but we take the partner in confidence in the policy decisions of the government," she said.

"I want to appeal to the centre to please take care of the people. Eleven times price rise of petrol and petroleum products in 12 months is unacceptable. Price hike may not affect the Central government, but it affects us in the states...We have a commitment to the people and we will never compromise on the question of imposing economic hardship on the masses," she asserted.

Banerjee, who till recently was the railway minister before being elected to state Assembly, said, "I am grateful to my parliamentary party that they have taken this bold decision (to quit UPA)."

She said she held discussions with union commerce minister Anand Sharma during the day.

"I have spoken to Union minister Jairam Ramesh following the latest hike in petrol price. My party colleague Mukul Roy last night also contacted union finance minister Pranab Mukherjee who pleaded helplessness in the matter."

Banerjee said she had informed the union commerce minister that any vital decision in absence of the prime minister should not have been taken by the centre.

"Taking a decision in absence of the prime minister brings a bad name for the country," she said.

Referring to yesterday's statement by union petroleum minister Jaipal Reddy hinting at a fresh hike in diesel and LPG prices shortly, she said, "Is it acceptable that the value of human being's will diminish and price of diesel rise?"

Banerjee said it was in the air that LPG price per cylinder would touch Rs 900 in the coming days. "This is serious."

She asked why petrol prices did not come down in India when crude prices fell globally.

Banerjee said, "Without consulting anyone the government unilaterally raises prices of petrol, kerosene oil, LPG and even coal... I kept quiet on many issues even after coal prices were raised recently. For two years, I tolerated this despite pressure being put on the common people."

The chief minister, who had earlier sought a special economic package to bail out the fund-starved state, hit out at the centre for stopping coal supply to power plants on the ground of non-payment of dues.

"Someone will have to take a lead role to uphold the people's cause. If we make a sacrifice and if that helps people, let it be so," Banerjee said.