Amid reports that Congress president Sonia Gandhi was "reluctant" to head the new government, the Communist Party of India-Marxist on Tuesday said the National Democratic Alliance was making "sinister attempts" to stall the appointment of prime minister.

CPI-M veteran Somnath Chatterjee also criticised Bharatiya Janata Party leaders Atal Bihari Vajpayee and Lal Kishenchand Advani for their "silence".

"There is a campaign of vilification" and "despicable" attempts were being made to "overrule the verdict of the people", the veteran leader said in New Delhi.