He lost to incumbent Clover Moore but beat the Greens and Labor, providing the Liberal Party with its best result in twenty years.

[3][12] In July 2012, Mandla was preselected by the Liberal Party for its City of Sydney mayoral candidate over Christine Forster, sister to former Prime Minister (at the time, Federal opposition leader) Tony Abbott.

[13][14] Mandla and Forster positioned themselves as an effective opposition to Lord Mayor Moore, who they claimed was concentrating too much on her vision of a "Sustainable Sydney" while losing track of practical problems, such as parking.

"[19] He argued that the plan to roll out tri-generation power plants across the city was extremely complex and could leave ratepayers paying hundreds of millions of dollars.

[24] In 2013, when wild fires destroyed hundreds of homes in New South Wales, Mandla convinced the council to increase its contribution to the Australian Red Cross NSW Disaster Relief from $100,000 to $200,000.

Mandla worked with Shooters MP Robert Borsak to help draft the bill, which was passed in September 2014 and was to take effect in the 2016 elections.

[28][29] Following the death of a whistleblower, Mandla pressured Mayor Moore to release the full details of a secret investigation into allegations of bullying and harassment within Sydney's parking ranger unit.

In May 2015 the whistleblower emailed Ms. Moore, City of Sydney CEO Monica Barone, and other officials to highlight plunging morale among colleagues, deteriorating mental health, high sick leave and staff turnover.

[30][31] In November 2015, Mandla announced that he would not run for Lord Mayor, citing the demands of his five board director roles and the upcoming birth of his seventh child as the reasons behind his decision.

[32] In July 2016, Mandla left the Liberal Party to run as the second candidate on independent councilor Angela Vithoulkas "Sydney Matters" ticket in the September 2016 council elections.