Downing Street is expected to reiterate its refusal to allow US military to attack civilian infrastructure from UK bases, exacerbating already fractious relations

Iran has threatened "much more devastating retaliation" if U.S. President Donald Trump follows through on his "power plants and bridges day" attacks.

The US president is in a delicate political position as the final hours to Tuesday's deadline for Iran to open the Strait of Hormuz tick down.