After the National and Provincial Elections on 8 May 2019, Mileham was appointed as Shadow Minister of the expanded portfolio of Mineral Resources and Energy.

Mileham matriculated with academic honours from Selborne College in East London in 1988 and went on to graduate with a Bachelor of Commerce (Legal) degree from the University of the Witwatersrand.

[3] Post studies, he commenced work for The Jupiter Drawing Room, a South African advertising agency, handling brands such as Coca-Cola and 5FM.

[11] After his re-election in 2014, Mileham was appointed the Shadow Minister of Cooperative Governance and Traditional Affairs by the new Leader of the Opposition, Mmusi Maimane.

[12] During tenure as Shadow Minister of COGTA, Mileham laid criminal charges against people involved in the VBS Mutual Bank scandal.

[14] On 21 June 2021, Mileham became a member of the Committee for Section 194 Enquiry which was established to determine Advocate Busisiwe Mkhwebane's fitness to hold office as Public Protector.