The Indian government is to open formal negotiations with the International Atomic Energy Agency over the implementation of a civil nuclear deal with the US, setting the stage for a clash with its Communist allies that is likely to lead to early general elections, analysts predicted on Monday.

The Communist parties that back the Congress-led United Progressive Alliance have warned of “serious consequences” if the government “operationalises” the agreement by negotiating safeguards with the UN’s nuclear watchdog, whose head, Mohamed El Baradei, arrived in India last night on a long-scheduled visit.