The 31-year-old PR guru looked cosy and casual in a black polo neck worn over a green satin fishtail skirt and black tights.
Symonds finished the look with an oatmeal-coloured wool blend herringbone coat and a pair of black suede Victoriana-style pair of lace-up ankle boots, both of which are from Marks & Spencer.
Since entering the political limelight, Symonds has made a habit of championing the British high street.
Carrie, who wore her hair in loose waves and added a pop of colour with pink lipstick, was accompanied into Downing Street by her dog Dilyn.
Follow the Evening Standard’s election coverage here.