Charles Young, from Fulham, was playing with his two-year-old son Max on a beach on the Isle of Wight two years ago when they were struck by a BMW driven by Paul Cambray (47).
The court heard that Cambray, who held a provisional licence, was attempting to park his car unsupervised when his foot slipped on the accelerator. The vehicle sped over a sea wall, killing Max and seriously injuring his father.
Now Young and his wife Antje, who witnessed the accident, are suing Cambray's insurer, Norwich Union, claiming he drove a high powered BMW which he was neither licensed nor competent to drive.
They also claim he drove unsupervised, failed to control the car properly, accelerated when it was unsafe, failed to brake, and continued to apply the accelerator after it had landed on Young, causing him additional injuries.
The writ has been issued by Websters solicitors.