a minority government consisting of the Centre and the DDP as well as some independents. They had to seek support from the MSPD and DNVP on a case-by-case basis. Pressure on Prussian policy came primarily from external factors. After the London ultimatum of 5 May 1921 regarding German payment of war reparations, Allied troops occupied Düsseldorf and Duisburg in the Ruhr. The assassination of former Reich Vice-Chancellor and Finance Minister Matthias Erzberger on 26 August by members of the far right Organisation Consul shocked supporters of the Republic. In September 1921 the MSPD cleared the way for a coalition with the DVP at its party congress in Görlitz. Otto Braun stated:What we are dealing with here is the conversion of our party from an acting to a governing party. This is very difficult for many because it takes us from a comfortable position to one that is sometimes very uncomfortable and full of responsibility. ... The comrades who speak against the resolution do not have sufficient confidence in the power of our party's appeal. We must have the will to power.After the MSPD withdrew support from the government in October 1921, accusing the Ministry of State of leaning towards the DNVP, negotiations began to form a grand coalition. On 5 November 1921, the MSPD and DVP joined the cabinet, and Stegerwald resigned. The opposition within the MSPD parliamentary group was considerable. Forty-six deputies voted for and 41 against the formation of a grand coalition. There were also significant reservations within the DVP. In the end, 197 of 339 deputies present voted for Braun as Minister President. Ministers were chosen from the MSPD, Centre, DDP and DVP. Carl Severing again became Minister of the Interior. Prussia's grand coalition proved to be a stabilizing factor in the Weimar Republic and contributed to its ability to survive the crisis year of 1923. The DVP remained loyal to the coalition even though it was courted by the DNVP to form a "citizens' bloc". An effectively functioning coalition committee successfully ensured that the different political interests were balanced, but despite the collegial cooperation, Braun and Severing dominated the government. The coalition lay claim to nothing less than a "Prussian democratic mission" for all of Germany. This was especially true after the murder of Reich Foreign Minister Walther Rathenau (DDP) on 24 June 1922, once again by members of the Organisation Consul. On the basis of