Wilkinson was born into a poor though ambitious Manchester family and she embraced socialism at an early age. After graduating from the University of Manchester, she worked for a women's suffrage organisation and later as a trade union officer. Inspired by the Russian Revolution of 1917, Wilkinson joined the British Communist Party, and preached revolutionary socialism while seeking constitutional routes to political power through the Labour Party. She was elected Labour MP for Middlesbrough East in 1924, and supported the 1926 General Strike. In the 1929–31 Labour government, she served as Parliamentary Private Secretary to the junior Health Minister. She made a connection with a young female member and activist Jennie Lee. Following her defeat at Middlesbrough in 1931, Wilkinson became a prolific journalist and writer, before returning to parliament as Jarrow's MP in 1935. She was a strong advocate for the Republican government in the Spanish Civil War, and made several visits to the battle zones.