After thoroughly checking the seriousness of Left parties' threat on the issue of the India-United States nuclear deal, Congress leaders have started whispering to the media that the Left leaders led by Communist Party of India-Marxist general secretary Prakash Karat are unlikely to change their stand.

The Congress leaders have started feeling that an early election in 2008 can not be completely ruled out. They have started thinking about various political permutations.

As things stand, the most interesting scenario for the Congress will be the possibility of seeing the nuclear deal through and then going in for an early election.

According to a highly placed source in the government, till Monday evening, there has been no compromise between the Left and the government. The Left parties want to put the deal on hold till the Hyde Act and its ramifications are fully discussed.

In other words, the Left wants to ensure that the government doesn't get too close to the US though the deal. At least as long as they are supporting it from outside.

So far, the Congress, Prime Minister Manmohan Singh [Images] and United Progressive Alliance chairperson Sonia Gandhi [Images] have reiterated that the nuclear deal is in the country's interest and that India needs energy. They have maintained that the deal does not compromise India's sovereignty in any way and have made it clear that putting the deal on hold will not be possible at all.

If the Left parties refuse to budge or the Congress refuses to shelve the deal then in mid-September, the Communists will finally withdraw support to UPA government.

At least two Left leaders have told so while talking to reporters in Parliament. They have said that the nuclear deal with the US is a "non-negotiable" issue and they will never support it.

It's expected that when experts from the International Atomic Energy Agency meet with Indian officials to discuss India-specific agreements, the Left may use their trump card and withdraw the crucial support from outside that gives stability to the government.

As a result, the government will turn instable and will be reduced to a minority government.

But even then, it will not come down because the earliest the Left parties are expected to withdraw support is only after the current session of the Parliament and also only if the government shows clear signs of going ahead and operationalising the deal.

However, it must be highlighted that the Left leaders -- particularly those of the CPM -- have not even once said publicly that they are thinking of withdrawing support to the government.

Karat has only said that the government will have to pay a heavy price. CPM politburo member Sitaram Yechury has always been saying that it's up to the government and the prime minister to decide on the future course with respect to the nuclear deal.

The most important thing is that before the winter session of Parliament, the government -- even if it is reduced to a minority -- can complete the formalities that remain to operationalise the deal. In a swift move, the deal can be operationalised by the minority government before the year-end, the source in the government claims.

Even as far back as July, the legal status of the 123 Agreement from the Indian side was cleared with Union Cabinet approving it and the Cabinet Committee on Political Affairs and the Cabinet Committee on Security giving it the formal nod.

The 123 Agreement contains all operational aspects of the nuclear deal that was agreed upon by US President George W. Bush and Indian PM Singh two years ago.

But even as the government sets the ball rolling and puts the deal through several stages abroad at the Nuclear Suppliers Group, the IAEA and at the US Congress, the Left parties will continue opposing the deal.

But on the basis of India's past record in upholding its international commitment, the Congress can expect that even if the government changes, the new government in its wisdom may not "dishonour" the deal.

When asked to comment, a senior Union minister from a regional party refused, saying that, "This is a hypothetical scenario. It's difficult to say anything at this juncture."