Nearly 150 tankers that make up the “shadow” fleet transporting Iranian oil will have to find alternative work if sanctions are eased, said BRS.

The ageing ships, which include some 45 VLCCs, are prime candidates for scrapping but could be re-routed to work moving Russian crude in the event of a political deal, said the French broker.

A revival of the 2015 nuclear deal — which would ease sanctions in return for tighter regulation of its nuclear programme — would allow Iran to resume mainstream trading of its oil on global markets.