"There are legal methods and the Guardian Council has enough time to review the cases carefully ... to prevent the violation of anyone's rights," state television quoted Khamenei as saying in a meeting with Guardian Council members on Wednesday.
The unelected hardline Guardian Council constitutional watchdog has barred reformist lawmakers from standing in the 20 February vote, triggering threats of mass resignations from cabinet members in recent days.
He said that in the case of MPs who are currently sitting in
parliament - 83 of whom have been barred from re-election -"if their aptitude was proved in the past, the principle is that they are still competent unless it can be proved otherwise."
Protest to continue
Khamenei, who has the final say on all matters of state and has directly or indirectly appointed all 12 members of the Guardians Council, also told the body not to go too far in applying its strict rules during the screening process.
Reformist MPs vowed to continue
Earlier, President Muhammad Khatami had appealed for reformist MPs to end their four-day sit-in over the move. But they swiftly rejected his conciliatory step.
Khatami had told MPs he was hopeful negotiations would bear fruit with the Guardian Council about its decision to bar almost half of the 8200 aspiring candidates from the race.
Most of Khatami's cabinet, including four vice-presidents and 12 ministers, have said they will resign within a week unless the election bans are overturned. State governors have issued the same warning.
But the Guardian Council said on Tuesday it would not be pressured into lifting the election bans.