The bottom line has turned red. UK gilt yields spiked to multi-year highs this morning as the bond market delivered a brutal verdict on the political vacuum at Number 10. The 10-year yield breached 4.5% for the first time since the 2008 crisis, a clear sign that international investors are demanding a risk premium for holding British debt. The trigger? Another round of infighting among Conservative MPs over the chancellor’s fiscal plans, leaving markets to conclude that no credible hand is on the tiller.
Let’s be clear: this is not a repeat of the Truss debacle, but it is a dangerous echo. Back then, unfunded tax cuts spooked markets. Now, the damage is self-inflicted by political paralysis. The OBR’s latest forecast already showed the UK on course for a £30 billion annual borrowing overshoot by 2026. Add a leadership contest that delays necessary spending cuts, and you have a recipe for capital flight.
Consider the mechanics. Higher gilt yields mean higher mortgage rates, higher corporate borrowing costs, and a tighter squeeze on household budgets. The Bank of England is now caught between fighting inflation and avoiding a sovereign debt crisis. If yields keep rising, the BoE may be forced to intervene with bond purchases, a move that would risk further devaluing sterling and reigniting inflation. That is the nightmare scenario: a fiscal dominance trap where monetary policy becomes subservient to government borrowing needs.
The market’s message is simple: sort out your house or we will sort it for you. The pound has already dropped 2% against the dollar this week. Foreign investors, who hold nearly 30% of UK gilts, are voting with their feet. They see a country with stagnant growth, high inflation, and a political elite more interested in internal battles than economic management.
What is to be done? The next prime minister must immediately signal fiscal credibility. That means a credible plan to reduce the deficit, ideally through spending restraint rather than tax rises, which would further damage growth. It also means a clear commitment to independent fiscal institutions. Markets hate uncertainty more than they hate austerity.
But the clock is ticking. Every day of infighting costs the Treasury an extra £100 million in higher interest payments on index-linked debt. The cost of inaction is compounding. If yields stay at current levels, the fiscal headroom for spending plans evaporates entirely. We are looking at a potential 1% of GDP increase in debt servicing costs by 2025.
In the trading rooms, the mood is grim. I spoke to a fund manager this morning who described the UK as ‘the sick man of Europe’ again. It is a harsh label, but not unjustified. Our friends in Brussels and Washington are watching with a mixture of concern and schadenfreude. They have seen this movie before, and they know how it ends when a developed economy loses its fiscal anchor.
The buck stops with the politicians. They must stop the circus and start the repair job. Otherwise, the market will do it for them, and it will be far more painful. For now, I am advising clients to brace for more volatility. The only safe haven in a storm is a strong balance sheet. Britain’s is looking shaky.
