President Pranab Mukherjee rejected Yakub Memon's mercy petition sent to him on Wednesday.

Activists and Memon's lawyers told the Supreme Court that after a mercy plea is rejected, the death row prisoner can't be hanged for 14 days according to rules.

However, others including the government say that rule applies to only the first mercy petition filed by the convict.

Last year, Memon's brother had filed a plea for clemency on his behalf which was rejected by the President.

Maharashtra jail rules call for a seven-day gap between the rejection of a mercy plea and the execution of the convict. However, top jail officials are entitled to waive this window.

The Supreme Court on Wednesday refused to stop Memon's hanging, rejecting his claim that the top court had not followed correct processes in upholding his death sentence earlier this week.

The same three judges who ruled against him during the day heard the emergency petition in the middle of the night.

Memon was convicted for helping finance the serial blasts in Mumbai in 1993 in which 257 people were killed. His brother, Tiger, and Dawood Ibrahim, who masterminded the blasts, remain missing.

Those who support Memon's claim say that he provided crucial information to investigators in fixing accountability for the blasts. Two of his brothers have been given the life sentence.