Datuk Seri Anwar Ibrahim has declared support for arch-nemesis Tun Dr Mahathir Mohamad in the latter’s bid to pressure Prime Minister Najib Razak to resign from his post.

The de-facto PKR leader said the call for change should involve reforms within key institutions in the country, which he deemed as 'been badly damaged'.

Anwar urged that the rights of the people should be returned through free and fair elections, as well as independent judiciary, free media.

READ: Tun Mahathir and wife quit UMNO

"I support the position of friends in civil society, political parties and individuals including Tun Dr Mahathir, Tan Sri Muhyiddin Yassin and others to build up strength and understanding together as articulated by the leader of the Opposition recently,” he said in a statement on Thursday.

Anwar also said that the economic policy should be reformed to refocus on fresh economic growth combined with equitable distribution of wealth.

READ: Tun Mahathir, opposition leaders set to sign joint declaration

Anwar is currently serving his five year jail term at the Sungai Buloh prison for sodomy.

Recently, leaders of several non-governmental organizations (NGO) had demanded Dr Mahathir to apologise to the rakyat for his actions when he helmed the country.

READ: 'UMNO's decision to suspend Muhyiddin cannot be challenged in court'

Dr Mahathir is scheduled to meet with opposition leaders and reps from NGOs Friday afternoon to sign a joint declaration in addressing current national issues.

READ: Tun Mahathir's decision to quit party 'not surprising' - UMNO Supreme Council