Zimbabwe's Opposition leader Nelson Chamisa is planning a parallel swearing-in, he told his supporters during a rally at the weekend.
The Movement for Democratic Change presidential candidate in the July 30 election says he will also form his own Cabinet.
The revelations, reported in Zimbabwe's Daily News website, came barely a fortnight after Emmerson Mnangagwa's oath.
The ZANU-PF frontman in this year's election assumed office on August 26 as president after the Constitutional Court - where Chamisa had challenged his win, ruled in his favour.
The court held that the MDC had no case and upheld Mnangagwa's election.
But the Daily News quoted Chamisa saying he will name his Cabinet in the coming few days, a situation that is likely to spark confrontations in Harare.
The city suffered violence after MDC supporters protested the vote outcome declaring Mnangagwa as the winner.
Such an action, similar to what ODM leader Raila Odinga did in Kenya on January 30, is treasonous.
Section 94 (1) of the Zimbabwe Constitution stipulates that persons elected as president and vice-presidents assume office when they take an oath before the Chief Justice or the next most senior judge available.
However, an adamant Chamisa has maintained that the MDC leadership is keen on having the "People's President" take the oath.
"When I am sworn in, I will take my own way and Mnangagwa will take his....we will see who the real leader is," Daily News quotes him in reports from the rally at Chitungwiza.
"I told Mnangagwa that we meet and resolve the issue but he refused. I am going to make life difficult for him. There is no stability out of rigged elections."
The MDC politician further held that the "Legal route does not declare Mnangagwa the winner."
Political observers in the country have cast doubt in the plan in the wake of former President Robert Mugabe's endorsement of Mnangagwa's presidency.
The former president backed Chamisa during the election but has since changed the tune. Several world leaders have also backed the current Zimbabwe leadership.
Voice of America quoted Chamisa’s spokesperson Nkululeko Sibanda as saying the "swearing-in" would be conducted by Zimbabweans and not the country’s chief justice or his deputy.
The two are supposed to administer the oath of office for a president as stipulated in the Constitution of Zimbabwe.