Political change in the UK over the past four months has added a layer of uncertainty that weighs on sterling and the gilt market. The UK’s political landscape shifted sharply in 2026. In May, the 30-year gilt yield briefly touched roughly 5.81% amid speculation over a Labour leadership challenge, and it surged past 5.78% again in early May when local election results intensified questions about Prime Minister Keir Starmer’s leadership. In July, Andy Burnham became Prime Minister and selected former Defence Secretary John Healey as Chancellor, replacing Rachel Reeves. That appointment kept gilt markets on edge over the future direction of fiscal policy. The September 8 auction of 30-year gilts at 5.8168% cut the Chancellor’s fiscal headroom to roughly £13 billion. Most economists now consider tax rises at the October 28 Budget highly likely, although their scale and form remain unclear. Higher debt interest costs leave less money available for public services, raise the prospect of higher taxes, or both. The fiscal inheritance adds to the challenge. The previous Budget, delivered in November 2025, raised taxes by £26 billion per year by the 2029–30 fiscal year, equal to 0.75% of GDP, but virtually none of those increases took effect in 2026. The Office for Budget Responsibility projected UK government debt rising from 95% of GDP to 96.1% by the end of the decade and downgraded growth forecasts for 2026 through 2029 to between 1.4% and 1.5% a year. The Debt Management Office projected gilt issuance close to or above £300 billion for each of the following three years.
The energy shock has worsened that picture. Higher oil prices raise inflation-linked debt costs, push up government spending on energy support and weigh on growth. The war with Iran has pushed borrowing costs up across the developed world, but the UK’s large share of index-linked gilts makes its debt costs especially sensitive to inflation. For the pound, the Budget creates a binary event six weeks out. A credible package of tax rises and spending restraint that restores fiscal headroom could narrow the gilt risk premium and support sterling. A package that fails to convince bond investors could trigger a repeat of past gilt market selloffs, pushing long-term yields higher and GBP/USD lower. Until October 28, uncertainty over that outcome caps sterling rallies. The political dimension also affects Bank of England policy. Aggressive fiscal tightening at the Budget would slow growth and reduce inflation pressure, strengthening the case for Bailey’s caution on further rate hikes. That dynamic further limits how far markets can price Bank of England tightening, keeping the rate differential tilted toward the dollar. The UK’s economic data has been stronger than expected, giving the pound one of its few fundamental supports. UK GDP grew 0.4% month over month in July, beating forecasts, and growth over the three months to July also held at 0.4%, according to the Office for National Statistics. A 0.4% quarterly pace annualizes to roughly 1.6%, above the Office for Budget Responsibility’s forecast growth range of 1.4% to 1.5% a year. The UK economy has absorbed the energy shock without contracting.
That resilience helps explain why three Monetary Policy Committee members voted for a hike in July. An economy growing at a solid pace while headline inflation rises toward 3.1% gives hawks a case that monetary policy is not restrictive enough. The six members who voted to hold pointed to contained core inflation and the risk that energy costs would eventually slow demand. The comparison with other economies is instructive. U.S. retail sales rose 1.2% in August, with the control group up 1.4%, and the U.S. economy continues to outperform. The European Central Bank upgraded eurozone growth to 0.9% for 2026 and 1.4% for 2027, citing resilience, but sees downside risks. UK growth sits between those two cases: firmer than the eurozone, softer than the U.S. The labor market is the missing piece for the Bank of England’s decision. UK employment and wage data released earlier in September shaped expectations for Thursday’s meeting. Services inflation at 3.4% suggests wage pressures remain present but are not accelerating. The energy exposure creates a medium-term growth risk. The UK is a net energy importer, and higher oil and gas prices transfer income out of the country. Brent crude at $107.60 and elevated natural gas prices raise household energy bills heading into autumn and winter. The energy price cap, which sets the maximum household tariff in Great Britain, adjusts quarterly and will reflect higher wholesale prices in the coming months.
Mortgage rates add pressure. Rising gilt yields filter through to fixed-rate mortgages, because lenders price those loans off swap rates tied to gilt yields. With 10-year gilts near 5.3%, UK mortgage costs are rising for households refinancing from lower fixed rates set in earlier years. For GBP/USD, stronger UK growth provides a floor rather than a catalyst. The pound fell to its weakest level since early August despite a 0.4% GDP print. Growth data would need to accelerate further, or the Bank of England would need to signal that growth justifies faster tightening, for it to lift sterling meaningfully. GBP/USD is trading within a broad dollar rally, and the cross-currency picture shows sterling performing in line with, not worse than, other majors. The U.S. Dollar Index reached 99.57 on Tuesday, its highest level since September 3, and traded mixed to firmer on Wednesday. The dollar has gained against every major currency this week. USD/JPY broke above 155.00 in Asian trading on Wednesday, a fresh one-week high. AUD/USD fell for a third straight session, defending 0.7100 near a monthly low. EUR/USD traded at 1.1540, near its weakest level in a month. Three forces support the dollar. U.S. yields are rising faster than most peers, with the 10-year Treasury at 5.045% on Tuesday. Rising U.S.-Iran tensions underpin the dollar’s reserve currency status. And U.S. economic data, from retail sales to consumer spending, continues to outperform.
The cross rates show sterling holding its ground against the euro. With EUR/USD at 1.1540 and GBP/USD at 1.3480, EUR/GBP trades at 0.8561. The European Central Bank raised its deposit rate to 2.50% effective today, while Bank Rate stands at 3.75%, leaving a 125-basis-point policy gap in sterling’s favor against the euro. Eurozone energy inflation spiked to 14.3% in August, pushing headline inflation to 3.3%. Sterling’s relative stability against the euro shows that its weakness is primarily a dollar story. Commodity and risk markets offer mixed signals. U.S. equities rose on Wednesday morning, with the S&P 500 up 0.5% and the Nasdaq up 0.9%, which would normally ease safe-haven demand for the dollar. Gold rallied 1.16% to $4,342.50, reflecting hedging against war, fiscal and policy risk. Brent crude eased to $107.60 from a four-month high of $109.21, which modestly supports sterling given the UK’s position as an energy importer. The global central bank calendar extends through Friday. The Bank of Japan is expected to hike to a 31-year high on Friday. A BOJ hike could trigger yen strength and partial unwinding of carry trades funded in yen, which would weigh on the broad dollar and provide indirect support for GBP/USD. For the forecast, the dollar index is the most important external variable. A DXY break above 100.00 after the Fed would correspond with GBP/USD trading below 1.3400. A DXY retreat below 99.20 would support a GBP/USD recovery above 1.3550.
