Baykal led the CHP through the 2002 general election, where the party won 19.38% of the vote and came second.
The newly formed Justice and Development Party (AKP), meanwhile, won a landslide majority in Parliament and put an end to years of unstable coalition governments.
Baykal subsequently became the leader of the opposition, leading the only opposition party in Parliament.
All other parties had fallen short of the 10% boundary, leaving the AKP with 363 and the CHP with 178 seats in the 550-seat Grand National Assembly.

Baykal was instrumental in assisting the AKP change the law in order to allow the party's banned leader, Recep Tayyip Erdoğan, to enter Parliament.
Erdoğan had been banned from public office due to religious intolerance, with the AKP needing 367 votes in Parliament to change the law in Erdoğan's favour.
The CHP supported the change and Erdoğan was elected to Parliament in a by-election in 2003, subsequently taking over from Abdullah Gül as Prime Minister.

Baykal has always held his ground as a staunch supporter of a strong response to terrorism.

Leading his party through the 2004 local elections, the CHP managed to increase their vote share but lost further ground, losing control of Antalya, Baykal's hometown, to the AKP.
As a result, the Mayor of İstanbul's Şişli district, Mustafa Sarıgül, challenged Baykal for the leadership in an extraordinary convention in January 2005.
Although Baykal won the election, the convention was marred by violence between supporters of the two opposing candidates, with Sarıgül being expelled from the party afterwards.
He first joined the DSP, but later formed the Turkish Change Movement in 2009.

Baykal strongly protested the AKP's nomination of Abdullah Gül as their presidential candidate for the 2007 presidential election, owing to Gül's history in political Islam.
The CHP held several Republic protests to rally against the parliamentary process, with CHP MPs boycotting the election process.
Due to the 67% quorum needed to elect a President, the AKP was unable to elect Gül without the CHP being in attendance.
As a result, an early general election was scheduled for July 2007.

Baykal joined forces in an electoral alliance with the DSP in time for the 2007 general election, though the two parties combined only marginally improving on their 2002 result, winning 20.88% of the vote.
Due to the Nationalist Movement Party (MHP) surpassing the 10% threshold, the CHP's seats dropped considerably from 178 to 112.
13 of the 112 MPs were from the DSP, meaning the CHP on its own held 99 MPs in Parliament.
However, many DSP MPs joined the CHP after being elected.
With the help of the MHP and DSP, Gül was elected President despite also suffering a loss in their share of the seats (down from 363 to 341), as there was a quorum of 67% this time.

The CHP's moderate vote share increase continued through the 2009 local elections, in which the party won 23.08% of the vote and won back control of Antalya.
The AKP lost further ground, most likely due to the 2008 global financial crash occurring a year before the election.
Despite presiding over an increase of the CHP's vote share in all elections he contested since 2002, he failed to win any of them.

He resigned from the leadership of CHP on May 10, 2010.
This was due to criticism of his private life after an alleged video-tape showing him in the same bedroom with his former secretary, and a member of parliament Nesrin Baytok, was leaked to the media.
He originally planned to run for the leadership again in the Ordinary Convention of 2010, since many members of the Central Executive Committee insisted that he retake his position as leader.
However, with many provincial branch leaders of the CHP endorsing Kemal Kılıçdaroğlu instead, Baykal refused to run for re-election and Kılıçdaroğlu was elected unopposed.
Baykal led the CHP through the 2002 general election, where the party won 19.38% of the vote and came second. The newly formed Justice and Development Party (AKP), meanwhile, won a landslide majority in Parliament and put an end to years of unstable coalition governments. Baykal subsequently became the leader of the opposition, leading the only opposition party in Parliament. All other parties had fallen short of the 10% boundary, leaving the AKP with 363 and the CHP with 178 seats in the 550-seat Grand National Assembly.
Baykal was instrumental in assisting the AKP change the law in order to allow the party's banned leader, Recep Tayyip Erdoğan, to enter Parliament. Erdoğan had been banned from public office due to religious intolerance, with the AKP needing 367 votes in Parliament to change the law in Erdoğan's favour. The CHP supported the change and Erdoğan was elected to Parliament in a by-election in 2003, subsequently taking over from Abdullah Gül as Prime Minister.
Baykal has always held his ground as a staunch supporter of a strong response to terrorism.
Leading his party through the 2004 local elections, the CHP managed to increase their vote share but lost further ground, losing control of Antalya, Baykal's hometown, to the AKP. As a result, the Mayor of İstanbul's Şişli district, Mustafa Sarıgül, challenged Baykal for the leadership in an extraordinary convention in January 2005. Although Baykal won the election, the convention was marred by violence between supporters of the two opposing candidates, with Sarıgül being expelled from the party afterwards. He first joined the DSP, but later formed the Turkish Change Movement in 2009.
Baykal strongly protested the AKP's nomination of Abdullah Gül as their presidential candidate for the 2007 presidential election, owing to Gül's history in political Islam. The CHP held several Republic protests to rally against the parliamentary process, with CHP MPs boycotting the election process. Due to the 67% quorum needed to elect a President, the AKP was unable to elect Gül without the CHP being in attendance. As a result, an early general election was scheduled for July 2007.
Baykal joined forces in an electoral alliance with the DSP in time for the 2007 general election, though the two parties combined only marginally improving on their 2002 result, winning 20.88% of the vote. Due to the Nationalist Movement Party (MHP) surpassing the 10% threshold, the CHP's seats dropped considerably from 178 to 112. 13 of the 112 MPs were from the DSP, meaning the CHP on its own held 99 MPs in Parliament. However, many DSP MPs joined the CHP after being elected. With the help of the MHP and DSP, Gül was elected President despite also suffering a loss in their share of the seats (down from 363 to 341), as there was a quorum of 67% this time.
The CHP's moderate vote share increase continued through the 2009 local elections, in which the party won 23.08% of the vote and won back control of Antalya. The AKP lost further ground, most likely due to the 2008 global financial crash occurring a year before the election. Despite presiding over an increase of the CHP's vote share in all elections he contested since 2002, he failed to win any of them.
He resigned from the leadership of CHP on May 10, 2010. This was due to criticism of his private life after an alleged video-tape showing him in the same bedroom with his former secretary, and a member of parliament Nesrin Baytok, was leaked to the media. He originally planned to run for the leadership again in the Ordinary Convention of 2010, since many members of the Central Executive Committee insisted that he retake his position as leader. However, with many provincial branch leaders of the CHP endorsing Kemal Kılıçdaroğlu instead, Baykal refused to run for re-election and Kılıçdaroğlu was elected unopposed.
Deniz Baykal