As a result, the KPD under Thälmann had a hostile, confrontational attitude toward the Social Democratic Party of Germany (SPD) as defenders of the capitalist status quo.

The bans appeared to affirm the official Communist Party line that capitalism had entered its Third Period, and the state would therefore become more draconian in obstructing efforts to organize the proletariat.

[5] The newspaper Die Rote Front stressed "the sharpened movement of the power organs of the capitalist state against the proletariat" in describing potential police violence against Communists.

The Internationale, the theoretical journal of the KPD, announced that the "revolutionary élan and will to fight among the German working class will show the Social Democratic police minister of the bourgeoisie [that] the proletariat cares nothing for their bans!

[8] SPD support for the ban, however, was not unanimous, given that a social democratic government was preventing public gatherings on an international holiday for working people.

[9] On 30 April 1929, police traffic officers were attacked at various places in Berlin by members of the RFB and the Young Spartacus League, the children's and youth organisation of the KPD.

While the ban on May Day demonstrations had been lifted in some parts of Prussia and the rest of Germany, Zörgiebel reaffirmed its validity for Berlin.

According to historian Thomas Kurz, the Social Democrats and trade unions had difficulties explaining the break with the tradition of May Day parades.

[15] Officers were at times insulted and provoked, and some demonstrators attempted to stop traffic by cutting tram lines and throwing obstacles into the street.

According to the liberal newspaper Frankfurter Zeitung, police cars continually rushed to Hermann Square in Neukölln, where officers jumped out and immediately began beating the people they found there.

[13] Law enforcement handled the defiance of the ban on open-air gatherings as if it were the popular revolt the Communist press had called for rather than the confused and haphazard act of civic disobedience that it was.

In the Wedding district, home to many Communist supporters, the violence gradually escalated into ongoing street combat, which included civilians erecting barricades.

They immediately imposed a seven-week ban on the primary Communist newspaper Die Rote Fahne ('The Red Flag') as a consequence of its incitement and also to hinder news of the high number of civilian casualties from spreading.

In the Reichstag, KPD member Wilhelm Pieck condemned Zörgiebel as a "common murderer",[21] while the SPD defended police leadership.

Although Zörgiebel called on the police to show moderation, he contributed to the escalation by placing large parts of Berlin under a state of emergency: "Persons walking on the street without a destination will be arrested.

The RFB, previously operating underground in fear of outright proscription, joined the clashes in Wedding during the afternoon of 2 May, once more constructing barricades in largely spontaneous defensive actions.

The harsh police suppression led to a furor in the Reichstag and the Prussian Landtag, with heavy media coverage by both independent and partisan newspapers.

Police found no evidence that the demonstrators who took to the streets were prepared for an armed insurrection, since the house-to-house search in Wedding produced mostly souvenir weapons from World War I.

[citation needed] The SPD had an equivalent to the KPD's social fascism claim in its leaders' anxieties over a new Spartacist uprising.

Although the KPD did desire to overthrow the Weimar Republic, extremist parties did not have the same appeal they had after the Great Depression of 1929 hit Germany.

The SPD government was convinced that the "Nazi wave will ebb", as evidenced by Grezesinski lifting the ban on Adolf Hitler speaking publicly in September 1928.

According to Chris Bowlby, "hysterical assessments" by SPD politicians of the threat posed by the KPD in combination with the militant nature of the Berlin police meant that conflict and even violence between the two groups was probable if not inevitable.