In 2011 John won gold and two bronze medals in the Europa Cup in St Moritz and was the first British man to ever do this.

[9] In January 2014 Jackson led team-mates Joel Fearon, Stuart Benson and Bruce Tasker to a silver medal in the four-man event at the Bobsleigh European Championship.

[10] He competed at the 2010 and 2014 Winter Olympics, guiding his crew to fifth place in the four-man event in 2014, 0.11 seconds off a bronze medal after recovering from a ruptured Achilles tendon.

In 2017, the British team were upgraded to the bronze medal position after two Russian crews were disqualified for doping violations.

He took a second place in the four-man competition at the Lake Placid round of the 2013–14 Bobsleigh World Cup, the first podium finish for a British crew for many years.