The leader of Turkey’s ultranationalist Victory party has endorsed the opposition candidate Kemal Kılıçdaroğlu, breaking ranks with the party’s former presidential hopeful Sinan Oğan, who endorsed Recep Tayyip Erdoğan. The Victory party leader, Ümit Özdağ, declared at a joint press conference with Kılıçdaroğlu that the two had signed a memorandum of understanding, including guarantees to deport all refugees in Turkey within a year of coming to power. They also agreed not to reinstate democratically elected Kurdish mayors in Turkey’s south-east previously replaced with appointees as part of a state crackdown on the leftwing and mostly Kurdish People’s Democratic party (HDP) – a swipe at the Kurdish support that buoyed Kılıçdaroğlu in the first round. “We reached a consensus with him. As the Victory party, we decided to support Kılıçdaroğlu in the second round,” he said. The HDP, whose jailed leader Selahattin Demirtaş previously endorsed Kılıçdaroğlu, said it would meet to decide how to respond. The split endorsement comes days before Erdoğan and Kılıçdaroğlu face a runoff round in the presidential elections on 28 May. In the first round Erdoğan attained just over 49.5% of the vote, ahead of Kılıçdaroğlu’s 44.5%. Oğan, who ran on a far-right explicitly anti-refugee platform, won just over 5% of the vote in the first round, and declared his support for Erdoğan earlier this week. “We believe that our decision will be the right decision for our country and nation,” he said. “I declare that we will support Recep Tayyip Erdoğan, the candidate of the People’s Alliance, in the second round of the elections.” The Victory party had backed Oğan but said at the time that Oğan’s statement did not represent the views of the party. Kılıçdaroğlu has already doubled down on his own anti-refugee rhetoric after the first round of voting, where both he and Erdoğan attempted to attract Victory party supporters to their side for the runoff. Days after his setback in the first round of voting, Kılıçdaroğlu pivoted away from his previous messages of inclusion and democracy and instead focused solely on his anti-refugee promises, reiterating a pledge to send refugees back to their countries of origin. Throughout his campaign, including at his largest rally in Istanbul, Kılıçdaroğlu declared he would expel all refugees in Turkey “within two years” of coming to power. When the Guardian asked how he intended to square this promise with a desire to join the European Union, he replied: “We do not think of this as racism. When we come to power, we will sit and talk with the legitimate administration in Syria and find a solution to this problem.” Following the signing of their agreement, Özdağ said Kılıçdaroğlu’s messages about sending refugees home had resonated with him. Both leaders cited vastly inflated figures for the numbers of refugees and asylum seekers currently in Turkey, estimated to be around 4 million, including at least 3.6 million Syrians under a temporary protection order imposed by Erdoğan. Just 2.2% of Turkish voters say refugees are the country’s biggest problem when polled, compared with more than 56% concerned about a profound economic crisis that saw the lira lose half its value in one year alone.