From 1994 to 1996, Pidgeon was a political researcher for Rose Colley, a councillor on
Southwark London Borough Council. Pidgeon was also a political researcher at
Brent Council from 1996 to 1999. She was employed at
Croydon Health Authority as a communications manager from 1999 to 2002, and undertook the same role at
Guy's and St Thomas' NHS Foundation Trust from 2002 to 2006. During her time on the Council, she served as deputy leader of the council (from 2002 to 2004), and as a cabinet member for Education (2004–2006) and Children's Services (2006–2008). In the same election, she was the third candidate on the party's London-wide party list and was thereby elected onto the London Assembly. Pidgeon was
re-elected in 2012 and
again in 2016. Following her election to the London Assembly, Pidgeon retired from Southwark Council at the
2010 local election. At the
2010 general election on the same day, Pidgeon unsuccessfully stood in the
Vauxhall constituency, finishing in second place. On the London Assembly, Pidgeon served as a member of the
Metropolitan Police Authority between 2008 and 2012 and the
London Fire and Emergency Planning Authority between 2008 and 2010. In September 2015, Pidgeon secured the Liberal Democrats' candidacy for the
2016 London mayoral election. Pidgeon promised to focus on housing, affordable childcare, air pollution and public transport. She emphasised the need to ensure that workers can live in the city by using rent control and reducing public transport costs. She ranked 13 out of 50 on the Top 50 Influential Lib Dems of 2020 list. Pidgeon was reelected as one of two Liberal Democrat members in the
2021 London Assembly election. In November 2022 she announced that she would not seek reelection in the
2024 election. Pidgeon assumed the role of chair of the
English Liberal Democrats on 1 January 2025. == Peerage ==