Wales Ambulance Service has to wait to hear the judge’s final ruling in a case which they have challenged a £1.8 million payout to the family of a man killed in a crash with an ambulance.

Gordon Williams 49, was killed in June 2001 when an ambulance collided with the car he was driving on the B4350 near Glasbury, Powys, in South Wales. He left behind a widow Jennifer now 59, and three adult children David, Sarah and Ruth. They were awarded a £1.8 millioncompensation settlement by a judge at Cardiff County Court in June 2007.

Mr Williams was a builders merchant and had built up a very successful business and property empire “from zero” the judge heard. He was worth an estimated £4 million before his death. The court heard he also had a passion for collecting steam engines and had a collection of vintage machines valued at an estimated £500,000. It was on his wealth and potential earnings that the settlement figure was based upon.

The Welsh Ambulance Services NHS Trust did not dispute liability for the 2001 accident in which Mr Williams of Hay-on-Wye, was pronounced dead at the scene. The ambulance was carrying no passengers but was responding to an emergency call.

The large compensation figure is being challenged by the ambulance service because they do not believe that Mrs Williams and her adult children are as heavily dependent on Mr Williams’s income as was made to believe in court. William Stevenson, acting on behalf of the ambulance service argued at the Appeal Court that the family business had been progressing since Mr Williams’s death and so the level of the family’s financial losses had been greatly overestimated by the court judge. He said that the settlement was effectively just a “windfall” for the family as David and Sarah Williams had taken over their father businesses and had had unexpected success.

Lady Justice Smith presiding over the case said that such an argument was not taking into account the immense energy and imagination of a man like Gordon Williams. She also said that no estimate could be put on the potential success he could have achieved in the rest of his life if he had not met his death prematurely. She added: “The underlying reality was Mr Williams had generated a huge amount of money from which his family all benefited and there was every reason to suppose he would have carried on doing so.”

She said to Mr Stevenson that there appeared to be a reality gap in his case, to which he replied: “Your ladyship has the last word”.

Judgement in the case has been postponed to a later unspecified date.