London stocks were flat by midday Monday as investors mulled political developments in Iran and news of a Department of Justice investigation into Federal Reserve chair Jerome Powell, with strength in the mining sector helping to keep the top-flight index afloat.
The FTSE 100 was steady at 10,122.20, paring earlier small losses. Gold hit a record high of $4,600 an ounce and silver also reached a fresh high. Sterling was up 0.5% against the dollar at 1.3471.
Powell said prosecutors had launched a criminal investigation into the $2.5bn renovation of the Federal Reserve's headquarters, and into his testimony about the project to the Senate banking committee in June last year.
The US president has repeatedly attacked Powell, whom he appointed in 2017, over the pace of interest rate cuts, claiming they needed to be lowered more quickly as part of a campaign to curb the central bank's independence.
However, Fed policy makers have resisted due to fears of inflation in the wake of Trump's global tariff war and a weak labour market. Rates were cut three times in the second half of 2025, but there are expected to be fewer cuts this year.
"This is about whether the Fed will be able to continue to set interest rates based on evidence and economic conditions, or whether instead monetary policy will be directed by political pressure or intimidation," Powell said in a video message.
"I have deep respect for the rule of law and for accountability in our democracy. No one, certainly not the chair of the Federal Reserve is above the law, but this unprecedented action should be seen in the broader context of the administration's threats and ongoing pressure."
Matt Britzman, senior equity analyst at Hargreaves Lansdown, said: "Sentiment has been shaken by news of a criminal probe into Fed Chair Jerome Powell and his claims of political pressure from the Trump administration, while unrest in Iran and talk of possible US intervention add another layer of concern."
Looking ahead to the rest of the week, attention will turn to US bank earnings, with JP Morgan Chase, Goldman Sachs, Citigroup, Morgan Stanley and Wells Fargo all slated to report.
In equity markets, precious metals miner Fresnillo shone, along with gold miners Hochschild and Endeavour.
Miners were also in the black as copper prices pushed towards $6 per pound, with Anglo American, Glencore and Antofagasta all up.
Britzman said prices were "supported by tightening supply and fresh concerns that new US tariffs on refined metals could reroute flows and strain global availability further".
"Disruptions across major South American producers, from weather to labour unrest, are adding to the pressure just as demand accelerates. And with copper sitting at the crossroads of two powerful structural trends, the AI build‑out and the global energy transition, it's the metal to watch for 2026," he added.
Plus500 rose after it said in a trading update that FY2025 revenue and earnings before interest, tax, depreciation and amortisation were ahead of market views.
Shares in Oxford Nanopore Technologies surged after the FTSE 250 firm said full-year sales had beaten guidance in 2025.
British Land fell as it said chief executive Simon Carter was leaving after five years in the role to head up a pan-European logistics firm.
Barclays slid after Trump called for a one-year 10% cap on credit card interest rates.
Russ Mould, investment director at AJ Bell, said: "The UK bank entered the US credit card market in 2004 with the acquisition of Juniper Financial and it is now one of the largest issuers in the country via partnership brands.
"While consumers would love to see lower rates on credit cards, Trump may not be able to enact such a move without approval from Congress. It also raises questions about the knock-on effect of a cap on credit and whether a drop in associated earnings for lenders could lead to reduced availability of credit in general, forcing some consumers and businesses to seek more costly alternatives."
Equipment rental firm Ashtead, which has significant exposure to the US, slumped.
In broker note action, Haleon was knocked lower by a downgrade to 'sell' at Deutsche Bank, while Mondi lost ground after a downgrade to 'underweight' at Morgan Stanley.
Educational publisher Pearson was boosted by an initiation at 'buy' by Citi, while Sage Group gained after an upgrade to 'buy' at UBS.
Harbour Energy gushed higher after an upgrade to 'buy' at SB1 Markets.