NEW DELHI, INDIA - INDIA'S Parliament will meet for a confidence vote in the government on July 21 and 22 after the government's leftist allies withdrew their support to protest against a United States nuclear deal, a minister said.

'This decision has been communicated to the president of India,' Mr Viyalar Ravi, the minister for parliamentary affairs, told reporters after a Cabinet meeting late on Friday.

A regional party has stepped in to replace Communists who opposed the nuclear deal, but Prime Minister Manmohan Singh's government still needs the support of smaller parties and independent lawmakers to survive the confidence vote.

The nuclear deal would be a landmark for India's relations with the West and allow India access to US civilian nuclear fuel and technology, despite not signing the Non-Proliferation Treaty and conducting nuclear tests in 1974 and 1998.

Trying to cobble a majority, government allies met on Friday with potential supporting parties, many of whom are keen to avoid polls at a time when inflation is at a record high.

'I have no doubt that we shall prove our majority,' Ms Sonia Gandhi, the ruling Congress party head and India's most powerful politician, was quoted as saying by the Press Trust of India.

The government's worries have been compounded by vacillation among some long-standing partners, worried the pact with the United States may alienate voters before elections next year.

The balance of power is held by the regional Samajwadi Party which said its 39 lawmakers would back the government. But it needs another seven votes from smaller parties for a majority.

'I think the government will survive the confidence vote, perhaps with around a 10-vote margin,' said analyst Kuldip Nayar.

India's main stock index fell last week in part due to the political uncertainty but has proven volatile as much on global economic factors as news of the Communists' exit.