A court in South Africa is hearing an opposition case that President Jacob Zuma should repay about $23m (£15m) of state funds used to renovate his rural home.
The President had offered to pay some of it back but the case, brought by opposition parties, is going ahead regardless.
Protesters, led by former Zuma ally turned fierce opponent, Julius Malema, are marching in Johannesburg on Tuesday.
A spokesman for Mr Malema’s Economic Freedom Fighters said that the demonstration was against “corruption and cronyism”.
But Mr Zuma’s ANC party called the planned march to the court a “political exercise”.
The case came at a difficult time for Mr Zuma, who had also been under fire over his handling of the finance ministry.
The BBC reports that the President sacked the respected Finance Minister, Nhlanhla Nene late last year, and appointed the little-known Des van Rooyen to the post in what critics saw as an attempt by him to increase his influence over the running of the country’s finances.
The decision led to the value of South Africa’s currency plunging and opposition groups calling for Mr Zuma’s resignation.
He bowed to the pressure by dismissing Mr Van Rooyen four days later, and appointing the highly regarded Pravin Gordhan to the post.
In 2014, a report by an independent watchdog said that Mr Zuma had “benefited unduly” from the upgrades.