derek harkinson, played by ian lavender, originally appears between 29 november 2001 and 19 may 2005. on 4 november 2016, it was announced that lavender had reprised the role for a guest stint during the 2016 christmas period, during which he would be reunited with martin fowler (now played by james bye). lavender commented, "it was a lovely surprise to be back and i had a great time. it was brilliant to work with some old friends again, especially those who i only briefly got to work with before." he returned from 15 november to 29 december 2016 and again on 23 march 2017. it was announced on 17 december 2017 that lavender would not be returning to the show.