Johari Abdul Ghani believes it was a mistake to allow former premier Najib Abdul Razak to campaign for BN in last week's Sungai Kandis by-election.
The former second finance minister said Najib is facing corruption charges, which could lead to a negative perception towards Umno.
Commenting on the comparison between Najib and DAP secretary-general Lim Guan Eng, who is also facing a corruption trial, Johari said Umno must aspire to a higher standard.
"My position is we don't have to emulate DAP. Umno has its own benchmarks and we should chart a new benchmark for Umno, which demands integrity and credibility from its leaders.
"We need to set such standards on all leaders to restore voter confidence in Umno – that it is a party which has higher standards than DAP," added the Titiwangsa Umno division chief in a statement.
Johari said Umno must overcome the negative perception towards the party's integrity and credibility in order to maintain relevance.
"We need to forget the era before the May 9 election. Umno has a new president and new leadership.
"The past president's era is history. If Umno doesn't change and defend its legacy – the cause of our rejection in GE14 – then it is possible that Umno too will become history," he warned.
Najib was actively stumping for one of his former lieutenants Lokman Noor Adam during the by-election.
Lokman was defeated by PKR candidate Mohd Zawawi Ahmad Mughni, and polled just 38 percent of the votes cast.