The Ethiopian parliament re-elected Meles Zenawi as prime minister for a third five-year term on Monday - but the main opposition coalition boycotted the new legislature's first sitting since disputed elections.
As expected, pro-Meles parliamentarians endorsed him in a show of hands, after which he took an oath of office during a formal inauguration ceremony.
Meles is to name his new cabinet on Tuesday.
Relations between government and opposition in sub-Saharan Africa's second most populous nation have been fraught since the May 15 poll, which brought claims of fraud and civil unrest in which security forces killed 36 people in June.
Attempts at a reconciliation before Monday's parliament session were aborted, with the opposition on Friday abandoning talks with Meles' ruling party.
Ethiopian President Girma Woldegiorgise - whose post is largely ceremonial - accused opposition parties of conspiring against the government. "In the aftermath of the third national elections, those who disputed the results have been engaged not in addressing their complaints through the provisions of the constitution, but through conspiracy and violence," he told parliament.