"Additionally Dr Mahathir's promises of a wholesale reform of the Malaysian political system is somewhat questionable, seeing as it was he who laid its groundwork to begin with", he said, as quoted by the Malay Mail Online.
Johor Baru Mentri Besar Datuk Seri Mohamed Khaled Nordin said Dr Mahathir has hijacked the opposition after the former premier was named as the coalition's choice for prime minister.
Sunday's announcement also saw Anwar's wife, Wan Azizah Wan Ismail, the People's Justice Party president, being named as the opposition's hopeful for the job of deputy prime minister, should the opposition win the election.
Anwar was Mahathir's deputy until he was sacked in a power struggle in 1998 and later imprisoned on charges of corruption and sodomy that Anwar said were trumped up.
The Mahathir-led opposition, however, looks unlikely to unseat the ruling Barisan Nasional (BN) coalition, according to a survey conducted by independent polling firm Merdeka Center in December.
Lajim who is also the State's opposition leader said he could not comprehend Dr Mahathir's stand when he had mentioned of retiring from politics and yet does not mind being named as the prime ministerial candidate after leaving the post nearly 20 years ago.
Anwar was once Dr Mahathir's protege and the rising star of Malaysian politics, but they had a falling-out in the late 1990s.
Malaysia's opposition leader Anwar Ibrahim is expected to be released from prison on June 11, an event that is likely to have implications for the country's political temperature. Anwar has condemned his convictions as politically motivated.
Mr Mahathir cut links with the ruling UMNO party and in 2016 started a new party, Bersatu, which joined the Pakatan Harapan opposition alliance.
Heavy snowfall strands tourists in Swiss Alps
DOMINIC STEINMANN, KEYSTONE, via EPA-EFE Heavy snow falls in Saas Fee village, near Zermatt , Switzerland on January 9, 2018. Ms Imesch added: "There is nothing to panic about, everything is fine".
Anwar later led an opposition alliance to stunning electoral gains in 2013.
Parliamentary elections will be held in Malaysia in August this year. Najib's coalition lost the popular vote in that election, but won a majority of the seats in parliament.
But Anwar was convicted and jailed again in 2013 for allegedly sodomizing a former aide, a charge he and his supporters describe as an attempt to end his career.
Mahathir stepped down as prime minister in 2003. A royal pardon, however, would let him contest.
This is the first time anyone has given an actual date for Anwar's release after serving a five-year sentence for sodomy.
Mahathir came out of retirement amid allegations that billions of dollars from state investment fund 1Malaysia Development Berhad (1MDB) were misused by Najib and others.
A political observer said although Dr Mahathir brought invaluable experience to the opposition table, the former premier was associated with many controversies and scandals that plagued his administration.
Government leaders scorned the candidacy of Mahathir, who will be the world's oldest leader if the opposition wins. Najib, the brainchild and head of 1MDB's advisory board, has denied any wrongdoing.