Anwar Ibrahim said Tuesday he was putting on hold plans to step aside as Malaysia's opposition leader, saying he wanted to spearhead a fight against poll results he says were tainted by fraud.
Anwar had said he would step down if the opposition failed to take power in Sunday's national elections, in which his three-party Pakatan Rakyat (People's Pact) won just 89 of 222 parliamentary seats.
But Anwar has claimed massive fraud by the Barisan Nasional (National Front) coalition, which has ruled the country without interruption for 56 years, tainted the results in many closely fought seats and cost the opposition victory.
"The context (to step down) was in a free and fair election. If the people decide to choose Barisan Nasional, then I would concede," he told reporters.
"(But) in a faulty, fraudulent election -- and we have compelling evidence to support that argument -- I now will continue the fight to defend the rights of all Malaysians."
Anwar has been credited with bringing together three disparate opposition parties to pose a real challenge to Barisan for the first time.
Though Barisan managed to capture a comfortable majority in parliament, it won just 48 percent of the popular vote compared with nearly 52 percent for the opposition.
The opposition and activists say this is due to gerrymandering. They also say indelible ink, which was introduced by the government in this election as a guarantee against multiple voting, was found to easily wash off.
Anwar has also claimed there was a scheme to fly tens of thousands of "dubious" and possibly foreign voters to sway the outcome in key constituencies.
Prime Minister Najib Razak has insisted the election was free and fair, dismissing the numerous allegations of irregularities and blaming the opposition as sore losers. He was sworn in by the king Monday.