The 24-year-old Australian clocked a fastest lap in one minute and 20.924 seconds.

It would be the first World Cup played on British soil since the men's finals in 1966, which were solely hosted by England.

But there are concerns among rugby chiefs about where the competition would fit into an already packed calendar.

Karp has, to date, ran 280 ultra-marathons, which include 29 Comrades marathons and 25 Two Oceans marathons.