Turkey's main opposition party vowed Tuesday to win the re-run of Istanbul's mayoral election, a day after the country's electoral council nullified the victory of party candidate Ekrem Imamoglu.

"We don't think that losing is an option because we have won the elections once and we are pretty confident that we are going to win again," Unal Cevikoz, deputy chair of the Republican People's Party (CHP), told DW.

"Mr. Imamoglu is not going to be the candidate of the CHP alone. He is going to be the candidate of all the people of Istanbul who are 16 million strong."

Read more: Opinion: Istanbul election re-do is a death knell for democracy

Erdogan's challenge

The re-run order came after the ruling Justice and Development Party (AKP) of President Recep Tayyip Erdogan alleged ballot "irregularities" and "organized corruption" in the March 31 vote.

Cevikoz, a former ambassador to the United Kingdom, said he was confident CHP could withstand "every measure" by the AKP to win the June 23 re-run.

"We are going to make sure that all the democratic forces of Istanbul join forces and this is going to put us on the winning side," he said.

Germany's support

Cevikoz also praised German Foreign Minister Heiko Maas and German lawmakers for voicing opposition to the original election result being scrapped.

"All this support is giving us morale. And we simply hope that this support should continue," he said.

The nationwide municipal and provincial votes in March also saw CHP win the mayoral post in the capital Ankara. AKP won most of the other races.

Tim Janszky contributed to this report.

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