The same day as Lumumba's appointment, the parliamentary opposition coalition, the , was announced. Though Kasa-Vubu was aligned with their beliefs, he remained distanced from them. The MNC-L was also having trouble securing the allegiances of the PSA, CEREA (), and BALUBAKAT (). Initially, Lumumba was unable to establish contact with members of the cartel. Eventually several leaders were appointed to meet with him, but their positions remained entrenched. On 16 June 1960, Lumumba reported his difficulties to Ganshof, who extended the deadline and promised to act as an intermediary between the MNC leader and the opposition. Once Ganshof had made contact with the cartel leadership, he was impressed by their obstinacy and assurances of a strong anti-Lumumba polity. By evening, Lumumba's mission was showing even less chance of succeeding. Ganshof considered extending the role of to Cyrille Adoula and Kasa-Vubu, but faced increasing pressure from Belgian and moderate Congolese advisers to end Lumumba's assignment. The following day, on 17 June 1960, Ganshof declared that Lumumba had failed and terminated his mission. Acting on Ganshof's advice, Baudouin then named Kasa-Vubu . Lumumba responded by threatening to form his own government and present it to parliament without official approval. He called a meeting at the OK Bar in Léopoldville, where he announced the creation of a "popular" government with the support of Pierre Mulele of the PSA. Meanwhile, Kasa-Vubu, like Lumumba, was unable to communicate with his political opponents.
