FACTBOX: Political scenarios over India-U.S. nuclear deal

NEW DELHI (Reuters) - The Indian government and its communist allies meet on Wednesday to break a deadlock over a controversial nuclear energy deal with the United States, a decision that could decide the fate of the ruling coalition.

The government depends on its communist allies to keep a parliamentary majority. Elections are due by May 2009 but the government coalition could be forced to call a snap vote if it loses support from the leftists.

Here are some political scenarios.

* Having invested heavily in the deal, India's government defies its communist allies and goes ahead with it. The communists withdraw their parliamentary support. The government

calls early elections, perhaps as soon as November.

The government has so far ruled this out, and early elections are seen as unlikely in the face of soaring inflation.

* Indian communists allow the government to negotiate an India-specific safeguards agreement with the International Atomic Energy Agency (IAEA), but not let the deal go any further. That would buy the government time and could avoid early elections. But the nuclear deal would probably have to be renegotiated after elections in the United States and India.

* The government formally ditches the deal, pleasing the communists and almost certainly guaranteeing a 2009 election.

* Prime Minister Manmohan Singh, who has invested a lot of his personal reputation with the deal, resigns even though his ruling coalition wants him to stay. That could produce a snap election or lead to the appointment of a caretaker prime minister.

(Compiled by Alistair Scrutton; Editing by Simon Denyer and Ben Tan)