John McDonnell is a British politician and a member of the Labour Party. He has served as the Member of Parliament (MP) for Hayes and Harlington since 1997. McDonnell is known for his role as the Shadow Chancellor of the Exchequer from 2015 to 2020, where he focused on economic policies aimed at reducing inequality and promoting public investment. Throughout his career, McDonnell has been an advocate for progressive taxation and social justice. He has been involved in various campaigns related to workers' rights and public services, often emphasizing the importance of government intervention in the economy to support disadvantaged communities.