By Dan Issacs
BBC News, Delhi
The Indian government is to hold talks with the UN nuclear watchdog, the IAEA, in Vienna on the controversial India-US civil nuclear deal.
The Left parties have been protesting against the nuclear deal
It is the next stage in the approval of the agreement which has run into serious domestic opposition in India.
Prime Minister Manmohan Singh's left-wing allies have opposed the deal, saying it will give the US too much influence over India's foreign policy.
On Monday, they agreed to government talks with the IAEA.
Mr Singh has defended the deal which would allow India access to US nuclear technology and described it as a "landmark".
It has already been pronounced dead and buried by some analysts - victim to domestic political rivalries and brinkmanship.
But Wednesday's talks in Vienna to iron out the wrinkles in the deal, to clarify who would be bound by what, and to explicitly set out the safeguards might just give the deal a new spark of life.
However, do not hold your breath.
India's communist parties say they retain the right to reject the deal even after the IAEA has sifted through it with a fine tooth comb.
Under the deal, Indian nuclear plants will be open to inspection
And if that happens, this last-ditch resuscitation attempt could yet prove fatal.
So what are the left's objections to the deal?
Primarily it is a question of Indian sovereignty.
The immense benefits of access to US nuclear know-how, they say, are being offered at too high a price.
US government committees would be able to scrutinise Indian government policy and could pull the plug on the supply of nuclear technology at any time.
More than this, say the deal's opponents, India - which is not a signatory to the nuclear non-proliferation treaty - would be bound by it by the back door, since if India were to carry out a weapons test, for example, the deal could be suspended.
And with nuclear rival Pakistan not constrained by the same conditions, the Communists argue, that would be untenable.
This nuclear deal has already been severely delayed by these domestic political wrangles and even if Mr Singh does eventually get parliamentary backing for it, the clock is fast running down.
The US Congress must also approve the final document.
But as America heads into an election year, the prospect of a Bush administration pushing through a highly controversial deal such as this will recede rapidly.