Musharraf, who is also the country's military chief, was quoted as telling Aaj TV, "About their return before elections, no, there is nobody returning before elections."
Bhutto and Sharif, both living in exile, are rivals of Musharraf and recently have been reported to be planning to return to fight in elections expected in October.
Musharraf has been reported to be negotiating a deal with Bhutto's party to gain support for his re-election, the BBC reported. Musharraf lately has come under intense political pressure both at home and abroad because of his suspension of the country's chief justice and allegedly for not doing enough to control Taliban-sponsored terrorism in neighboring Afghanistan.
The BBC said observers feel the any likely deal with Bhutto may now be in question after the weekend political violence in Karachi in which 41 people died. The city is one of the strongholds of Bhutto's party.