KUALA LUMPUR - Selangor's ruler on Wednesday (June 20) waded into a controversy involving the appointment of the state's new menteri besar, in an unusual move by a Malaysian sultan to defend his action.

His explanation is closely watched after the Malaysian King, Sultan Muhammad V, was recently accused by critics of not closely adhering to the country's Constitution by delaying the appointment of a new prime minister after the ouster of Barisan Nasional.

The King was later accused of delaying the appointment of a new attorney-general.

Sultan Muhammad V denied both accusations, saying he had adhered closely to the Constitution.

In the Selangor case, the state's Sultan Sharafuddin Idris Shah on Tuesday swore in assemblyman Amirudin Shari, who is from Parti Keadilan Rakyat (PKR), as the new chief minister.

PKR is one of the four parties grouped under the Pakatan Harapan (PH) alliance that governs Malaysia as well as Selangor, the country's most industrialised state.

But another Selangor assemblyman from PKR, Dr Idris Ahmad, 71, called a news conference at around the same time as the swearing-in ceremony to say that he was the consensus menteri besar candidate approved by PH.

He showed reporters documents to prove that he had support of the other leaders of Selangor PH.

Dr Idris claimed that Mr Amiruddin, 38, was only accepted by the PKR faction led by deputy president Azmin Ali, implying that Sultan Sharafuddin should not have accepted Mr Amiruddin's ascension.

Dr Idris is from the PKR faction led by party president Wan Azizah Wan Ismail, who is at odds with Mr Azmin on leadership issues.

Explaining the ruler's action, the Selangor Palace on Wednesday said the Sultan based his decision on a letter it received from Dr Wan Azizah on June 7 over the selection of the new menteri besar, reported the Malaysiakini news site.

Sultan Sharafuddin said in the statement issued by the palace that this letter superseded earlier letters he had received over the appointment.

"The letter dated June 7 by the PKR president had also indirectly cancelled out earlier letters by the heads of Selangor political parties to His Majesty," the palace said, according to Malaysiakini.

In her letter, Dr Wan Azizah sought the ruler's consent to grant an audience with any candidate that Sultan Sharafuddin viewed as qualified to lead the state, based on the Selangor Constitution.

The new Selangor leader was appointed after the former menteri besar, Datuk Seri Azmin, stepped down as he is now the federal Economic Affairs Minister in the Mahathir administration.

The Selangor palace said that based on the June 7 letter, and having considered the views of Mr Azmin, Sultan Sharafuddin appointed Mr Amirudin.

The statement from the palace said the Sultan, as provided by the Selangor Constitution, has discretionary powers to appoint the menteri besar.

Dr Wan Azizah, who is also Malaysia's Deputy Prime Minister, said on Tuesday that the appointment of Menteri Besar Amiruddin should be allowed to "run smoothly".

"Because I think we have waited for some time and I think the former menteri besar (Azmin) cannot handle being a minister as well as a menteri besar, even though he is sad to leave."

"So let it run smoothly and properly," she told The Star newspaper in an interview.