Turkey’s main opposition leader Kemal Kilicdaroglu faces the tough task of enlisting crucial Kurdish support for his bid to unseat President Recep Tayyip Erdogan without antagonizing nationalist voters in the diverse opposition bloc that nominated him as a joint candidate in the upcoming elections.

The Peoples’ Democratic Party (HDP), whose mainly Kurdish base is seen as a kingmaker in the May polls, has expressed readiness for dialogue with Kilicdaroglu in what is emerging as the opposition’s strongest challenge yet to Erdogan’s two-decade rule. Yet collaboration with the HDP, which risks being outlawed for alleged links to armed Kurdish militants, remains a hot-button issue for the six-party Nation Alliance, which includes nationalists hostile to the HDP.

The alliance came back from the brink of collapse on Monday after its second-largest member, the nationalist Good Party, backed down from objections to Kilicdaroglu’s nomination as a joint candidate. The Good Party, however, remains staunchly opposed to letting the HDP join the alliance or negotiating any HDP terms in return for its support. Nevertheless, the party’s leader Meral Aksener has left the door open to individual contacts between Kilicdaroglu and HDP leaders.

Amid his sagging popular support, Erdogan could count on two scenarios to win reelection. The first is the Good (Iyi) Party abandoning the opposition alliance — a prospect that appeared imminent last week when Aksener fired broadsides at her allies for insisting on Kilicdaroglu as a presidential candidate. But after a weekend of political drama, she stepped back in return for the nomination of her favorites — Istanbul Mayor Ekrem Imamoglu and Ankara Mayor Mansur Yavas — as vice presidents.