Local media previously reported that speculation is rife of a plot to topple the government.
News portal The Vibes on April 24 alleged that there were plans to remove Mr Anwar from his position via by-elections among Barisan Nasional (BN) MPs who did not support him.
According to the report, several BN MPs were being wooed and persuaded to quit their parties and sacrifice their seats. The MPs would then reportedly seek re-election under the opposition Perikatan Nasional (PN) banner.
Earlier on Monday, Mr Anwar said that the parties in his unity government are strong enough to defend against any plot to topple the government.
“As far as we can see, the position (of the government) is quite strong,” Mr Anwar was quoted as saying by Bernama.
On Wednesday, Johor ruler Sultan Ibrahim Ibni Almarhum Sultan Iskandar expressed concern over the recent “incessant reports regarding the stability of the current (Malaysian) government”.
“The rakyat (citizens) placed high hopes in the recent General Election and voted for 222 representatives to bring back political stability to the country.
“But until today, the 222 MPs cannot get on the same page with efforts made to derail the stability that is being carefully built,” said Sultan Ibrahim in a Facebook post.
Mr Anwar was sworn in as prime minister on Nov 24 last year after the 15th General Election failed to produce a clear winner.
He leads a unity government comprising his Pakatan Harapan coalition and the previous ruling coalition BN, among other parties. Other parties and coalitions that currently back the unity government include Gabungan Parti Sarawak, Gabungan Rakyat Sabah and Parti Warisan.