The Ukrainian parliament has approved a package of laws paving the way for a snap election on 30 September.
The two Viktors have put aside their differences for now
Prime Minister Viktor Yanukovych and President Viktor Yushchenko agreed last weekend on the poll, in an effort to end a long-running political crisis.
In April the president dissolved parliament, accusing his rival of trying to usurp his power.
Parliament completed approval of the legislation for a new vote just before a deadline set by Mr Yushchenko.
He became president in January 2005 following the pro-democracy Orange Revolution, which overturned a rigged victory for Mr Yanukovych.
But Mr Yushchenko accepted his rival as prime minister after the president's allies failed to win a majority in the March 2006 election, and the two men have repeatedly clashed.
The president favours closer ties with the West, while the prime minister is seen as more pro-Russian.
Their rivalry threatened to turn violent last month, when Mr Yushchenko announced his intention to take control of 40,000 interior ministry troops.
The crisis appears to have been defused by Sunday's deal to hold the election.