After university, Hayes worked as a town planner. She became managing partner of her own town planning company, Urban Practitioners, before becoming a partner at London architectural practice Allies and Morrison.[7]
Before being elected as an MP, Hayes was elected as a Councillor for the college ward of Southwark Council[8] in 2010 and in 2014.[9][10] Following her election as an MP in 2015 she held both roles for 10 months before resigning as a Councillor in March 2016 to focus on her Parliamentary duties.[11]
At the snap 2017 general election, Hayes was re-elected as MP for Dulwich and West Norwood with an increased vote share of 69.6% and an increased majority of 28,156.[18][19]
In 2018, Hayes criticised the closure of two Royal Mail delivery offices in her constituency.[20]
Hayes was again re-elected at the 2019 general election, with a decreased vote share of 65.5% and a decreased majority of 27,310.[21]
Hayes is married to Ben Jupp; the couple have two children.[5] Her sister-in law is Rachel Jupp, editor of the BBC current affairs series, Panorama.[27]