[4] Labour's search for a new candidate was triggered by the decision of sitting MP Linda Riordan in February to stand down on health grounds.

[15] She was reappointed to the front bench by Labour leader Jeremy Corbyn on 3 July 2017, taking on the role of Shadow Flooding & Coastal Communities Minister within the Environment, Food and Rural Affairs team.

[16][17] In 2018, Lynch led the Protect the Protectors campaign to secure harsher sentences for people convicted of assaulting emergency service workers.

[18] In the House of Commons chamber, she spoke about the experience of her parents, both of whom were emergency service workers who had faced violence whilst on the job.

[21] Lynch endorsed Keir Starmer in the 2020 Labour Party leadership election,[22] and was appointed as the Shadow Minister for Immigration following his victory in April 2020.

[23] She held this position until the minor reshuffle in May 2021, when she swapped roles with Bambos Charalambous to become the Shadow Minister for Crime Reduction and Courts.

[25] Since her appointment, she has focused on issues such Boris Johnson's relationship with Alexander Lebedev, hostile state threats, Martyn's Law and the effectiveness of the Criminal Injuries Compensation Authority (CICA).