Widdows began his career with an MG Midget and a Lotus 23 winning the "Autosport" Class C Championship in 1965. He moved to Formula Three the following year and in 1967 competed in Formula Two with a Brabham BT23, winning the Rhine Cup at Hockenheim. In 1968, Widdows joined The Chequered Flag team to compete in a McLaren M4A and that year took part in his only World Championship Grand Prix, for Cooper, in the British Grand Prix at Brands Hatch but retired with ignition problems. He returned to Formula Two the following season with Bob Gerard and also raced sportscars for Matra. Widdows continued in Formula Two in 1970, with a Brabham, but retired from the sport part way through the season.