South Africa's African National Congress (ANC) plans to take an art gallery to court over a satirical depiction of President Jacob Zuma, according to local radio reports.
The 1.85 metre portrait, titled The Spear shows Zuma in a Soviet-style pose with his private parts hanging out of his trousers.
The ANC has labelled the work by artist Brett Murray "an insulting depiction of the president" and says it violates his constitutional right to privacy and dignity.
The party is demanding that the Goodman Gallery, where the painting is on display, takes it down. It has also asked the City Press newspaper to remove a photograph of the work from its website, Talk Radio 702 reported.
"It is a sad day for South Africa when creative production is being threatened with censorship from our ruling party," Goodman Gallery curator Liza Essers said on Twitter.
Murray has angered the ANC in the past with a print that showed a "for sale" splashed over the party logo.
South Africa's politicians are regularly depicted in a satirical manner in the country's newspapers.
A shower head extends from Zuma's head in the work of cartoonist Zapiro. It is meant to mock the president for once having said he bathed after having unprotected sex with a woman infected with the HIV virus.