Swarbrick joined the BBC in 2009 as a producer and presenter on local radio.[6] He joined LBC in June 2012 initially as a journalist before becoming Chief Correspondent in 2015.[6] He then presented his own afternoon show on the weekend between 12 and 3pm, becoming the youngest presenter of a national talk radio show.[6][citation needed]
Swarbrick returned to LBC in spring 2018 to present the weekend breakfast show.[9]
In August of that year, he moved to LBC's late-night 10pm to 1am weekday slot, replacing Ian Collins, and began a new Sunday morning programme called Swarbrick on Sunday.[7]
In September 2022, Swarbrick moved to drivetime, 4pm to 6pm, replacing Eddie Mair, who retired after 40 years of broadcasting.[7] Swarbrick was replaced by Colin Brazier in the Sunday morning slot.[10]
In 2018, Swarbrick was accused of sharing questions prior to an interview with a Cabinet Minister, in an attempt to get him on his show. According to Buzzfeed, Swarbrick made assurances "that the minister would be safe and the interview would be gentle."[11] He also interviewed the then Prime Minister, Theresa May, shortly after re-joining LBC.[11]
In April 2022, Nathan McGovern, an activist from Just Stop Oil, glued himself to the microphone during an interview with Swarbrick. McGovern claimed he was taking a stand again the station because it was not promoting the climate crisis.[12]
During his time at the BBC, Swarbrick was nominated for a Sony Radio Academy Award. Swarbrick was named National Radio Journalist of the Year at the 2014 Radio Academy Awards for his documentary on people-trafficking in London.[6][13] He was also named International Reporter of the Year.