Cox made her maiden speech in the House of Commons on 3 June 2015, using it to celebrate her constiuency's ethnic diversity, while highlighting the economic challenges facing the community and urging the government to rethink its approach to economic regeneration.[16] She was one of 36 Labour MPs to nominate Jeremy Corbyn as a candidate in the Labour leadership election of 2015, but said at the time that she had done so in order to get him on the list and encourage a broad debate.[17][18] However, in the election she voted for Liz Kendall,[19] and announced on 6 May 2016 after the local elections that she and fellow MP Neil Coyle regretted nominating Corbyn.[20]