Johannesburg , South Africa ( CNN ) -- Thousands of people are expected to march Tuesday in South Africa to protest a portrait of President Jacob Zuma that shows his genitals . Zuma 's supporters in the ruling African National Congress say the portrait is insulting and call it an attack on both the president and his party . About 15,000 people are expected to participate in the march to Johannesburg 's Goodman Gallery , where the work was on display , according to the South African Broadcasting Corporation . The painting by artist Brett Murray , called `` The Spear , '' is reminiscent of Soviet-era propaganda posters . Red on one half and black on the other , the painting shows Zuma in a proud stance with his genitals prominently exposed . Attorney weeps as he argues for censoring painting . The painting was defaced last week after a storm of protests and condemnation , the SABC reported . `` We believe all these actions by the gallery are not only a violation of the right to dignity of ... President Jacob Zuma but are a clear and calculated attack on the ANC , '' the party said on its website . `` We therefore again call on all South Africans , members and ( supporters ) of the ANC and our alliance partners to come and register their outrage at this insult and attack on our president and the ANC , '' it said . The Sunday newspaper City Press removed the image of the portrait from its website after the ANC threatened a boycott , but it complained Monday the ANC still wants the paper to apologize for running it in the first place . Democratic Alliance , the ANC 's official opposition , said The Spear `` was brilliant as a work of political satire , which is also why it became an instant icon . '' Calls for the painting 's censorship , the party said , indicate a dangerous move away from the right to free speech . If he felt insulted , Zuma should have sued the artist rather than calling for the painting 's removal , the Democratic Alliance said .
The portrait shows President Jacob Zuma with his penis exposed . The ruling party says the painting is insulting . They say 15,000 people are expected to march in protest .