The Russian oil price cap has failed because of a central flawed theory that Western maritime services were too vital for Russia to ignore, a parliamentary inquiry has heard.

Richard Bronze, founder of commodity data firm Energy Aspects, said the migration of the tanker trade from Western service providers to “shadow operators” exposed the failings of the scheme.

“The theory was there but I think, in practice, it just hasn’t worked,” Bronze told a committee assessing the success of the UK’s sanctions regime against Russia.