UK Prime Minister Keir Starmer announced his resignation on Monday. A series of strategic missteps during his tenure could fill a substantial volume, with the root of most being a miscalculation: the belief that the UK economy, battered by the Ukraine war in 2023, was poised for a strong rebound, allowing for both rapid growth and easy fiscal consolidation. Investors are now awaiting further news on the successor following Starmer's resignation. On Tuesday, the British pound edged lower against a strengthening US dollar. Simultaneously, the composite Purchasing Managers' Index (PMI) indicated a contraction in UK business activity this month. The challenges Starmer faced are not over; with the Iran conflict now easing, his successor may face a similar test – and must ensure the government projects firm control over the situation. Starmer's resignation paves the way for an orderly transfer of power. The newly elected MP for Macclesfield, former Greater Manchester Mayor Andy Burnham, is expected to take over as Prime Minister. It remains unclear whether Burnham will face a formal leadership contest or if potential rivals will step aside. His most significant potential challenger, former Health Secretary Wes Streeting, withdrew from the race on Monday, stating his support for Burnham. Tommy von Bromsen, a currency strategist at Swedish commercial bank SEB, noted, "The path for Burnham to become the next prime minister is clear, and I think the market is relieved about that."

The Incoming Leader's Economic Reality Test

Burnham advocates for greater state control over utilities and proposes increased taxes on property, wealth, and investment income. However, he has pledged to adhere to the fiscal constraints framework established under Starmer, including balancing day-to-day spending and putting the debt-to-GDP ratio on a downward path. As these rules are judged against official forecasts rather than actual revenues and expenditures, the UK's independent fiscal watchdog, the Office for Budget Responsibility (OBR), will continue to act as the ultimate arbiter of fiscal credibility. Recently, the OBR's forecasts have significantly influenced policy, with last autumn's budget causing turmoil due to downgraded productivity predictions. A less scrutinized issue, however, is whether Starmer's various pledges were built on overly optimistic forecasts. A key pledge was to rule out increases to income tax and value-added tax, which has left government officials scrambling to balance the books. One solution was to raise employers' National Insurance contributions, a move that angered the business community and contributed to higher inflation and interest rates in 2025. Looking back to 2024, expectations for a robust economic recovery were not unreasonable. The departure of the pro-Brexit Conservative government offered new hope for foreign investment; inflation had fallen back to target, with consumer spending poised to rebound; the OBR forecast GDP growth would rise from 0.3% in 2023 to 2% in 2025, pulling people out of the welfare system and into employment. The reality, however, has been continued cautious household spending, rising disability benefit costs, food inflation, and a new energy shock from the Middle East, clouding the economic outlook and keeping interest rates elevated. By March of this year, the OBR had already downgraded its growth forecast for this year to just 1.1%. Certainly, any government can be unlucky, and Starmer's administration implemented several policies popular with its base, such as taxing businesses to fund welfare, expanding workers' rights, building renewable energy capacity, and controlling immigration. But using economic variables entirely outside its control as a benchmark for success was a strategic error. Now, Burnham may face a similar trap: if a US-Iran peace deal holds, economic data for 2027 could suddenly improve, and a business-friendly Chancellor of the Exchequer candidate – such as former Health Secretary Wes Streeting – could help soothe bond markets. However, merely fine-tuning taxes and subsidies is unlikely to help Burnham win the 2029 general election. For that, he needs to replicate the "visible achievements" of his time governing Manchester, such as radical reform of social housing. In any case, he must chart his own course – relying too heavily on macroeconomic tides can easily steer a ship straight onto the rocks.

Pound Under Pressure, UK Business Activity Contracts Again

At the time of writing, the pound was down 0.2% against the US dollar at $1.3222, slightly above the low of $1.31635 hit on Friday, its weakest level since March. The pound was largely flat against the euro at 86.27 pence. SEB's von Bromsen stated, "Looking ahead, the market focus will shift to the choice of Chancellor, but I think most candidates are sufficiently cautious not to cause market turmoil. We are not going to see a repeat of the Truss chaos." He was referring to the crisis in September 2022 under former Prime Minister Liz Truss's brief tenure when the pound plunged to a record low against the dollar. Traders on the betting site Polymarket see the race for the new Chancellor as a two-horse contest, with Streeting given nearly a 70% chance and Ed Miliband around 20%. Francesco Pesole, a currency strategist at ING, noted in a report, "Streeting is generally perceived as a more market-friendly candidate than Miliband, who is reportedly the other main contender for the Chancellor role." The next prime minister will inherit a UK economy showing signs of fatigue. On Tuesday, the S&P Global composite PMI showed business activity contracted at its fastest pace since April 2025 in June, dragged down by continued weakness in the services sector. The combined services and manufacturing index fell from 49.7 to 49.4; the services PMI dropped from 49.3 to 48.7, its lowest level since January 2023. A PMI reading below 50 indicates contraction. Rob Wood, chief UK economist at Pantheon Macroeconomics, said, "The S&P Global survey shows business confidence remained depressed in June by political uncertainty. Therefore, Starmer's resignation earlier this week may help alleviate business concerns about a chaotic leadership transition." However, he added, "There remains huge uncertainty about Burnham's policy agenda, and we think businesses will remain in wait-and-see mode for months to come, weighing on GDP growth."