Yakub Memon, convicted in the 1993 Mumbai serial blasts, on Thursday moved the Supreme Court challenging the death warrant for his execution on July 30.Seeking a stay of the execution, Memon sought quashing of the death warrant on the grounds that due procedure was not followed for issuing it.The apex court on Tuesday rejected Memon's curative petition saying that it was void of merit. On the same day, Memon filed a mercy petition before the Maharashtra governor seeking commutation of his death sentence into life imprisonment.Memon in his petition before the Supreme Court submitted that death warrant was issued before he could exhaust all his legal remedies. It was issued and the day of execution for July 30 was fixed even as his curative petition was still pending in the Supreme Court.Earlier this year, the apex court had quashed death warrant issued for two death row convicts in a multiple murder case on the grounds that it was illegal as procedure was not followed.