He was a member of the Parliament of Finland, representing the Socialist Electoral Organisation of Workers and Smallholders 1927–1930 and the Finnish People's Democratic League 1945–1948.

After the war, Pekkala and Väinö Hakkila opened a law firm in Helsinki to help the captured Red Guard fighters.

In the late 1920s, Pekkala was active in the Left Group of Finnish Workers which criticized the underground Communist Party of Finland.

[2][3] On 5 July 1930, the fascist Lapua Movement kidnapped Pekkala and Jalmari Rötkö from the meeting of the Constitutional Law Committee and took them to their headquarters in the Ostrobothnia province.

On the following day, Pekkala and Rötkö were handed over to the authorities, after the Minister of Interior E. V. Kuokkanen gave an order to arrest all 23 STPV parliamentarians.

His clients included Pellervo Takatalo, Aimo Rikka and Martta Koskinen who were all given the capital punishment.

Pekkala managed to change Takatalo's and Rikka's sentences for life in prison, but Koskinen was executed in September 1943.

[6][7] As the war was over, the Communist organizations were legalized, and Pekkala was re-elected to the Parliament in the 1945 parliamentary election representing the Finnish People's Democratic League.