``So far, only the BJP has advocated a policy of exercising the nuclear option,'' the Communist Party of India (Marxist) and the Communist Party of India said in a joint statement.

Demanding that the Vajpayee Government adhere to the country's nuclear disarmament policies which have been pursued so far, the two parties called for the avoidance of a nuclear arms race in South Asia so that peace and security is maintained in the region.

``Our concern is that the ongoing process of normalising relations with India's neighbours might be jeopardised,'' said Communist Party of India national secretary, D Raja.

Questioning the decision to carry out the tests at this juncture, the CPM and the CPI said the Government has not given any reasons for this decision nor has it explainedthe international and national implications that would result as a fallout of the test.

While felicitating the Indian scientific community, the two parties reiterated that India had successfully developed its independent capability in the nuclear field. Meanwhile, the Janata Party also asked the BJP Government to explain how the potential international political leverage would be utilised to ``ward off the counter-measures of (our) adversaries.''

``Nuclear tests and bomb stockpiles are useless unless we have a strategic doctrine regarding how it should be used,'' Janata Party president Subramanian Swamy said in a statement.

Warning that the ``raw tribal euphoria'' following the tests would die down, Swamy said the Prime Minister should unravel the broad contours of a global strategic policy. Subramaniam Swamy said that otherwise the nuclear tests would mean ``nothing more than reckless adventurism that hurtles us to a confrontation that the nation is not prepared for.''

``If the Prime Minister hasno blueprint for such a policy, this adventurism will harm the nation,'' Swamy contended.