Manmohan Singh, India's Prime Minister, heads to the G8 summit in Japan today having apparently salvaged a historic nuclear deal with the United States after a vintage bout of Indian political brinksmanship.

In a meeting on the sidelines of the summit on Wednesday, Mr Singh is expected to tell President Bush that the deal they agreed in 2005, allowing India to buy U.S. nuclear technology and fuel, is finally back on track.

Mr Singh's breakthrough not only reduces the threat of a government collapse and early elections in India: it also offers President Bush the possibility of a rare foreign policy victory in his last weeks in office.

The deal would cement a new strategic relationship between Delhi and Washington - ideological rivals during the Cold War - and result in billions of pounds worth of contracts for U.S. and European nuclear suppliers.

Until the weekend, it appeared to be dead because the Communist parties that support India's ruling coalition in parliament had threatened since last year to withdraw that backing if Mr Singh activated the pact.

The Communists, whose withdrawal would leave the government short of a majority, forcing a no-confidence vote, say the deal will give Washington too much control over India's foreign policy and nuclear programme.

But after a frantic week of backroom negotiations, the Congress Party that leads the coalition persuaded the Samajwadi Party (SP), a former adversary based in the eastern state of Uttar Pradesh, to back it over the nuclear deal.

"We will not vote against the government, even if the communists and other parties do," Amar Singh, the SP general secretary, told reporters in Delhi on Saturday.

"The (nuclear) deal is in the interest of the nation, we should have come out in support of the deal a year ago."

The last-minute alliance highlights the vagaries of Indian coalition politics, which analysts often list among the biggest obstacles to the country's continued development.

The ruling coalition controls 226 seats in the 543-member lower house of parliament, but relies on external support from the Communists' 59 seats to give it a majority.

With the SP controlling 39 seats, the government now has to find at least another seven in order to maintain its majority and win a no-confidence vote if the Communists pull out.

It must also seek approval for the nuclear deal from the International Atomic Energy Agency and the Nuclear Suppliers Group, both of which it is likely to approach this week.

Mr Singh is expected to ask Mr Bush on Wednesday to help speed that process.

The big question is whether there is time for the U.S. Congress, whose last session begins in September, to approve the nuclear deal before the presidential election in November.

U.S. officials have repeatedly warned India that time is running out -- and that if Barrack Obama wins the White House, he will come under pressure to modify or even shelve the deal.

Several prominent Democrats oppose the agreement because India, which tested nuclear devices in 1974 and 1998, has not signed international nuclear non-proliferation agreements.

Gary Ackerman, a U.S. Congressman who met Indian leaders last week, said that the deal needed to be tabled in Congress by September at the latest.

"We have a calendar. The calendar is running quickly," said Mr Ackerman, who heads the House Foreign Relations Sub-Committee on South Asia.

"We had been hopeful that the processes will move quickly...(but) the processes have moved slower than we had hoped because of obvious reasons."

In India, meanwhile, the concern is over what concessions Mr Singh granted the SP and whether they will further restrict the government's options ahead of national elections, due by May.

Among other things, the SP is believed to have demanded the removal of the Finance and Petroleum Ministers and the head of the central bank.

"The true test of the Prime Minister comes now," wrote Vir Sanghvi, a prominent columnist, in the Hindustan Times.

"Can he now show India that he will use those extra months to do more than just push the nuclear deal through? Will he control prices? Will he give back a worried nation its dream of prosperity?"

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