President Robert Mugabe, who's been ruling Zimbabwe for 28 years, is to be sworn in at 1300 GMT on Sunday in Harare for his fifth term in office. Watch France 24's special coverage live.
Tsvangirai immediately rejected the invitation, saying the inauguration was meaningless after an illegitimate poll. He said he would ask the African Union not to recognise Mugabe's re-election.
Mugabe's spokesman, George Charamba, told Reuters the invitation was "done in the spirit of the president's wish to reach out...It is a major step towards political engagement."
The veteran Zimbabwean leader is under heavy pressure from within
"Well, you know that the whole inauguration is meaningless as far as I'm concerned, so I can't give support to an exercise I'm totally opposed to... the whole world has condemned it, the Zimbabwean people will not give this exercise legitimacy and support," Tsvangirai told Reuters.
He said the opposition was committed to African Union sponsored talks with Mugabe's government although no negotiations had started.
Analysts said before Friday's vote that Mugabe defied a chorus of calls to call off the one-candidate election so that he could negotiate with Tsvangirai from a position of strength.
Pan-African parliament observers, one of the few groups able to monitor the ballot, said the vote on Friday was so flawed it should be rerun.
Results have not been released, but Mugabe said he was heading for victory in the poll, dismissed as a sham by much of the world.
The government said Mugabe's swearing-in for a new five-year term would be held at 3 p.m. (1300 GMT).
The inauguration would allow Mugabe to extend his 28 years of unbroken rule before attending an African Union summit in
Mugabe was the only candidate after Movement for Democratic Change leader Tsvangirai withdrew because of government-backed violence which he said had killed nearly 90 of his supporters.
"These elections were not free and fair," said Marwick Khumalo, head of the Pan-African parliament observer team.
"Conditions should be put in place for the holding of free, fair and credible elections as soon as possible."
Date created : 2008-06-29