In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.

Passage: Shortly after the return home in November 1936 Riley, together with three other Jarrow councillors who had led the march—James Hanlon, Paddy Scullion and Joseph Symonds—left Labour to form a breakaway group committed to a more direct fight for employment. All four later rejoined the party; Scullion and Symonds both served as the town's mayor, and Symonds was Labour MP for Whitehaven from 1959 to 1970. In 1939 Wilkinson published her history of Jarrow, The Town that Was Murdered. A reviewer for The Economic Journal found the book "not quite as polemical as one might have expected", but felt that in her denunciation of the BISF Wilkinson had not taken full account of the state of the iron and steel industry in the 1930s. Wilkinson continued her parliamentary career, and from 1940 to 1945 held junior ministerial office in Churchill's wartime coalition government. In the 1945 Labour government she was appointed Minister of Education, with a seat in the cabinet, a post in which she served until her death, aged 55, in February 1947.
In 1974 the rock singer Alan Price released  the "Jarrow Song", which helped to raise awareness of the events of 1936 among a new generation. Among dramatisations based on the Jarrow March is a play, Whistling at the Milestones (1977) by Alex Glasgow, and an opera, Burning Road (1996), by Will Todd and Ben Dunwell. In what Perry describes as one of the ironies surrounding the march, the opera was performed in Durham Cathedral in May 1997, in retrospective defiance of the bishop who had condemned the march. On 29 October 2017, the Tyne Bridge was closed off and was the venue the Freedom on The Tyne Finale. The Freedom on The Tyne Finale was the finale of the 2017 Freedom City festival. The event, promoted by Newcastle University re-enacted many world civil rights stories throughout history. The final event, revolved around the March, the re-enactment was described as a memorable closing to the finale. The town of Jarrow contains several commemorations, including a steel relief sculpture by Vince Rea at the new railway station, a tile mural designed by local schoolchildren, and a bronze sculpture—"The Spirit of the Crusade" by Graham Ibbeson—in the town centre. Buildings and street names bear the names of Wilkinson and Riley. Perry writes that "In Jarrow, landscape and memory have fused together, just as the red hot rivets once fastened great sheets of steel in Palmer's Yard.".
What were the last names of the four people that led the march and formed a breakaway group?