The CHP-DSP alliance was announced at a news conference on Thursday by the Republican People's Party (CHP) and Democratic Left Party (DSP).
The election date in Turkey is 22 July.
Opinion polls indicate the AKP is still Turkey's most popular party.
"We have agreed to form an election alliance. We will work together hand in hand," said CHP leader Deniz Baykal.
Last Mod: 17 Mayıs 2007, 17:42