Record debt interest payments pushed public borrowing higher last month amid fears that Labour leadership changes and the Iran war could drive up debt even further. Rachel Reeves borrowed £24.3bn in April to plug the gap between tax revenues and public spending, according to the Office for National Statistics (ONS). This was £3.4bn higher than the £20.9bn forecast by the Office for Budget Responsibility (OBR) in March, just as the Middle East conflict began. The war in Iran has sent government borrowing costs surging on bond markets as investors braced for higher inflation. The ONS showed the Government paid £10.3bn on debt interest repayments, which was the highest for any April on record. Fears about higher public spending have also unnerved investors in UK debt. However, Andy Burnham has sought to allay fears by pledging to stick with the tax and spending rules outlined by the current Chancellor.…