The opposition Social Democrats in Germany have voted overwhelmingly in favour of entering a grand coalition government with centre-right chancellor Angela Merkel.
A new government can now be formed, three months after September's general election.
The chancellor's Christian Democrats (CDU) and their Bavarian sister party, the Christian Social Union (CSU), won the 22 September poll, but fell short of a majority. They needed a partner and spent much of the last three months negotiating a coalition deal with rival SPD, which came a distant second.
The SPD said 76% of its members who took part in the unprecedented postal ballot voted to join forces with the conservatives despite initial misgivings.
Thanks to what analysts called a clever strategic move to ask grassroots members to vote on the coalition, the SPD forced Ms Merkel to accept many of the SPD's leftist policies, Reuters reports.
A "no" vote could have plunged Germany into crisis and complicated European Union efforts for a banking union reform that would see the European Central bank police the sector with a new agency to shut down weak lenders.
The coalition agreement is due to be signed on Monday and Merkel's new government could be sworn into office on Tuesday.