Harare , Zimbabwe ( CNN ) -- Zimbabweans voted Saturday for a key referendum on a new constitution that limits presidential terms for the first time in the African nation . Robert Mugabe , 89 , has been in power for decades , first serving as prime minister in 1980 and taking over as president seven years later . `` This is a Zimbabwean document to replace a British one . That is why I voted for it , '' said Babra Mheno , 34 , a university student , referring to the nation 's former colonial rulers . If approved , which is highly likely , the constitution will give more powers to the parliament and limit the president 's . It also introduces a two-term limit of five years each for a president . The limit will not apply in retrospect , which means Mugabe has 10 more years as head of state if he is re-elected . `` I have voted no for the document , '' said Kizito Marwe , at a polling station east of Harare . `` It was written by politicians , not Zimbabweans . '' The 27-year-old said he 'll spend the rest of the day taking advantage of the public holiday . `` I was in line for two hours . I am heading home and spending the day watching TV , '' he said . Mugabe has indicated he will run for re-election during the polls scheduled for between July and October . The referendum -- one of the conditions set before an election -- clears the way for the first poll since a disputed outcome plunged the nation into chaos in 2008 . The upcoming election will end the fragile coalition between Mugabe and Prime Minister Morgan Tsvangirai . Both entered a power-sharing agreement in 2009 after regional leaders nullified Mugabe 's victory , citing violence by his loyalists targeted at rival supporters . The two leaders are expected to run for president . About half of the nation of 12 million is expected to vote in the referendum . The referendum also addresses gender equality , and sets aside 60 parliamentary seats for women out of a total of 310 . In days leading up to the referendum , Mugabe shut out Western observers , but allowed monitors from African nations to take part . Sporadic reports of violence have marred campaigns in the days leading up to the election . `` We should not have violence ... the party will not tolerate that nonsense ( political violence ) whether it is intra-party or inter-party , '' Mugabe said in a statement this week . CNN 's Nana Karikari-apau contributed to this report .
If approved , which is highly likely , the constitution will give more powers to the parliament . It will also limit the power of the president . The new government would be formed by a coalition between two parties that are currently in opposition : the Democratic Party and the Nationalist Party.