PKR president Anwar Ibrahim said today that he did not have the heart to replace Dr S Streram as the candidate for the Rantau by-election due to his humanitarian work.

"Why did I still choose him? Looking at his history, he is a Hindu of Indian descent, but he volunteered to go to Afghanistan to help Muslims who were hurt," he said at an event in Mambau to introduce the Pakatan Harapan candidate.

"He went to Syria as a volunteer to help those who were hurt. He is a medical doctor who helps the needy and Muslims in need.

"Where has (acting Umno president) Mohamad Hasan gone? That was why I did not have the heart to change Streram," he told the crowd of 500.

The Rantau by-election was called following a decision by the Election Court to void Mohamad's win in the 14th general election.

This was after the returning officer had prevented Streram from entering the nomination centre to file his nomination papers, resulting in a walkover for Mohamad.

The Umno leader is expected to defend the state constituency against Streram.

There were grassroots efforts to field a different candidate for Harapan in the by-election, but Anwar ultimately decided to stick with the anaesthesiologist.

According to Streram's biodata, he had served with Doctors Without Borders in Afghanistan, Hong Kong and Sudan.

Nomination day for the Rantau by-election is set for March 30. Voters go to the polls on April 13.