A process of cabinet formation took place in the Netherlands after the cabinet crisis over the public broadcasting system led to the resignation of the Marijnen cabinet on 27 February 1965. The formation resulted in the Cals cabinet on 14 April 1965. The coalition was formed by the Catholic People's Party (KVP), the Labour Party (PvdA) and the Anti-Revolutionary Party (ARP).

After the 1963 general election, a cabinet formation led to the Marijnen cabinet, comprising Catholic People's Party (KVP), People's Party for Freedom and Democracy (VVD), Anti Revolutionary Party (ARP) and Christian Historical Union (CHU). Prime minister was Victor Marijnen (KVP). The parties could not agree on the introduction of commercial television, advertising on television and the introduction of new broadcasters, which became more urgent with raid of REM Island in 1964. Minister of Education, Arts and Sciences Theo Bot had promised to send a proposal to the House of Representatives before 1 March 1965. Because of Marijnen's absence, the discussion started relatively close to the deadline. When presented in the cabinet, the VVD ministers in particular disliked Bot's proposal. On 27 February 1965, Marijnen concluded that the differences could not be bridged and offered the resignation of the cabinet.

The House of Representatives received a brief letter about the resignation, but the opposition had little knowledge of what happened. Therefore, PvdA leader Anne Vondeling requested a debate on 1 March. When no ministers showed up to the debate, Vondeling requested the presence of the prime minister. This request was support by all parliamentary leaders except for Molly Geertsema (VVD). Marijnen attended the debate, but spoke no word. Even the statement that he would remain silent was read aloud by the speaker of the House. The opposition asked for the information, but the coalition parties opposed this.

Queen Juliana had waited with consultations until after the debate. Almost all advisers and parliamentary leaders advised the queen to attempt a reconstruction of the cabinet. Almost all of the parties recommended a new cabinet if a reconstruction failed, to avoid new elections. Options mentioned for a new cabinet where KVP–ARP–CHU, KVP–PvdA–ARP and KVP–VVD–CHU. The PvdA was reluctant to govern with the confessional parties, after events during the 1963 cabinet formation. Vice-President of the Council of State Louis Beel, Vondeling, Geertsema and ARP parliamentary leader Jan Smallenbroek recommended KVP parliamentary leader Norbert Schmelzer as informateur, while another four adviser had recommended Beel. Schmelzer had recommended a VVD informateur, following the motto "he who breaks, pays", but he was alone in that advice.

On 2 March, Schmelzer was given the assignment of informateur, limited to reconstructing the Marijnen cabinet. This meant he had to solve the broadcasting issue. He met with Bot for the substantive side, and with Marijnen and ARP deputy prime minister Barend Biesheuvel for the political side. He then met with Geertsema on 8 March, who stated the desires of the VVD. He relayed these desires to the other parliamentary leaders of the coalition. Afterwards, Geertsema claimed he had not given permission to share his (written) desires, although Schmelzer claimed he had gotten permission and this was later supported by both their notes. Kees van der Ploeg - who temporarily replaced Schmelzer as parliamentary leader - and Smallenbroek rejected the VVD desires and interpreted them as demands. The first round of meetings thus only increased the differences between the parties.

Schmelzer then organised a meeting with the parliamentary leaders of KVP, ARP, CHU and VVD. It lasted until the early hours of 12 March. It was at that time nicknamed the "Night of Schmelzer", later renamed to the "first Night of Schmelzer" when the more famous Night of Schmelzer took place in October 1966. The parties were not able to bridge the differences during that meeting. The next day, Schmelzer handed in his assignment. Not only did he note that reconstruction was not possible, he also indicated that a coalition of KVP, ARP and CHU was not possible because CHU sided with VVD in the discussion. Schmelzer received blame for how he acted as informateur, among other things because he only took inventory of the differences, but did not come up with solutions to bridge those differences.

The situation left practically no other option than a coalition with the PvdA, despite hesitations from both the PvdA and the confessional parties. During the second consultation round, Vondeling advised the queen to appoint Schmelzer as formateur, focusing first on forming a coalition with only the KVP, ARP, and CHU. Geertsema also recommended Schmelzer as formateur but emphasised a coalition with the PvdA. CHU leader Henk Beernink believed that the 76 seats held by the KVP, ARP, and CHU were insufficient and preferred to refusing to discharge the cabinet. Schmelzer, having returned as parliamentary leader, suggested naming a member of the CHU as formateur, likely blaming them for the crisis as well. The CHU formateur would then focus on forming a cabinet with the KVP, PvdA, ARP, and CHU. All other leaders also pointed to Schmelzer, but he refused.

As an alternative, Schmelzer suggested KVP MP and former minister Jo Cals on 13 March, who had supported cooperation with the PvdA in 1963. Although Cals was hesitant and his wife felt he should refuse, he decided to accept the role the next day. On that same day, he was flown back by government plane from Rome, where he had travelled the previous day, and met with the queen. Cals was reluctant because most recommendations had pointed to Schmelzer, and he did not want to become prime minister, a likely outcome if he became formateur. He requested to be appointed as informateur instead, but Juliana refused. Ultimately, Cals yielded and was appointed formateur with the broad assignment to "form a cabinet that could count on fruitful cooperation with parliament".