The Chancellor has warned against risks to financial stability in the UK after the economy unexpectedly grew in March, official figures show. Rachel Reeves responded to new growth figures to say “now is not the time” to risk instability amid a possible leadership challenge against Prime Minister Sir Keir Starmer . It comes as economists warned the pace of growth is set to stall throughout the year as the impact of the Iran war begins to show. Gross domestic product (GDP) increased by 0.3% in March, the Office for National Statistics (ONS) said, showing a surprise uplift for the first full month after the start of the US-Israeli conflict with Iran. This helped the economy grow by a higher-than-expected 0.6% over the first quarter, between January and March. This marked the strongest growth since the first quarter of 2025 and came in ahead of the 0.5% rate that analysts had been expecting.…