UK long-term borrowing costs have hit their highest level since 1998 as global oil prices near Iran war peaks as a result of fears of extended disruption to flows from the Middle East.

The yield – the interest rate demanded by investors to hold 30-year government bonds – stood above 5.7% ahead of Wednesday’s close while its 10-year counterpart also hit its highest since July 2008, according to the Reuters news agency..

The UK is not alone in facing bond market pressure as a result of the strains facing economies from rising energy prices but its yields, the highest in the G7 of advanced economies, reflect additional investor concern over the state of the public finances and sticky inflation that has long preceded the Iran war.