The opposition on Monday slammed the government over the 'one nation, one election' issue, saying it was not possible under the present Constitution and just a "gimmick" of the ruling BJP which keeps "releasing hot air balloons" to test waters. The Congress, the TMC and the CPI rejected the idea, saying it was not pragmatic. The opposition parties' assertion came after reports said the BJP-led National Democratic Alliance (NDA) government would implement 'one nation, one election' during its current tenure. Senior Congress leader P Chidambaram said it is not possible under the present Constitution and requires at least five constitutional amendments. Replying to a question on reports that the BJP-led NDA government would implement 'one nation, one election' within its current tenure, he said Prime Minister Narendra Modi does not have the numbers to place those constitutional amendments either in the Lok Sabha or the Rajya Sabha. Addressing reporters in Chandigarh, Chidambaram said