Stock prices in London closed higher on Friday, as a swathe of domestic economic data was well-received and the US Supreme Court ruled President Donald Trump’s tariff programme is illegal.

The FTSE 100 index closed up 59.85 points, 0.6%, at 10,686.89.

The FTSE 250 ended up 178.07 points, 0.8%, at 23,751.56, and the AIM all-share closed up 3.97 points, 0.5%, at 815.11.

In European equities on Friday, the CAC 40 in Paris closed up 1.4%, while the DAX 40 in Frankfurt ended 0.9% higher.

The pound climbed to 1.3492 dollars on Friday afternoon from 1.3455 dollars at the equities close on Thursday.

The euro stood slightly higher at 1.1780 dollars from 1.1768 dollars.

Against the yen, the dollar was trading marginally higher at 154.95 yen compared to 154.90 yen.

The US Supreme Court ruled that President Donald Trump exceeded his authority in imposing a swathe of tariffs that upended global trade, blocking a key tool the president has wielded to impose his economic agenda.

The conservative-majority high court ruled six-three in the judgment, saying the International Emergency Economic Powers Act “does not authorise the president to impose tariffs”.

While Mr Trump has long used tariffs as a lever for pressure and negotiations, he made unprecedented use of emergency economic powers upon returning to the presidency last year to slap new duties on virtually all US trading partners.

These included “reciprocal” tariffs over trade practices that Washington deemed unfair, alongside separate sets of duties targeting major partners Mexico, Canada and China over illicit drug flows and immigration.

The court on Friday noted that “had Congress intended to convey the distinct and extraordinary power to impose tariffs” with IEEPA, “it would have done so expressly, as it consistently has in other tariff statutes”.

The ruling does not impact sector-specific duties that Mr Trump has separately imposed on imports of steel, aluminium and various other goods.

Formal probes which could ultimately lead to more such sectoral tariffs remain in the works.

“The Supreme Court ruling on Trump’s tariffs will unlikely be a big game changer for markets,” said Ebury analyst Matthew Ryan.

“Not only was the decision broadly expected, but the president has already signalled that he will quickly pivot to other legal tools to achieve similar trade restrictions, and he has at his disposal multiple levers to pull in order to circumvent the verdict.”

“This means that while we could see some near-term disruption, his long-term tariff strategy is unlikely to be derailed so long as the White House can replicate the regime through alternative methods.”

Meanwhile, Mr Trump said he is contemplating a limited military strike on Iran, in case a deal on its nuclear programme is not reached.

Asked by a reporter if he is “considering a limited military strike if Iran doesn’t make a deal,” Mr Trump answered: “The most I can say – I am considering it.”

Back in the UK, a torrent of positive economic data was in focus.

Analysts said positive retail sales and purchasing managers’ index data for the UK provided further evidence that economic activity picked up in the new year as uncertainty from the Government autumn budget faded.

Retail sales increased 1.8% on-month in January, compared with a 0.4% rise in December and far outstripping the consensus forecast for a 0.2% rise.

The flash UK purchasing managers’ composite output index rose to a 22-month high of 53.9 points in February from 53.7 in January, beating the FXStreet-cited market consensus of 53.4 points, which would have meant a deceleration of growth.

Climbing further above the neutral 50-point mark separating growth from contraction, it indicates the pace of activity accelerated in February.

“Retail sales provide further evidence that economic activity is picking up smartly in the new year as budget uncertainty fades,” said Pantheon Macroeconomics analyst Rob Wood.

Stocks in New York were higher.

The Dow Jones Industrial Average was slightly higher, the S&P 500 index was up 0.4%, and the Nasdaq Composite 0.8% higher.

The yield on the US 10-year Treasury widened slightly to 4.09% on Friday from 4.08% on Thursday.

The yield on the US 30-year Treasury widened to 4.73% from 4.71%.

US economic growth was slower than expected in the final quarter of the year, though separate numbers showed inflationary pressure picked up in December, giving the US Federal Reserve some food for thought.

Gross domestic product rose 1.4% on an annualised basis quarter-on-quarter, the Bureau of Economic Analysis said, slowing from a 4.4% rise in the third quarter, and below FXStreet cited expectations of a 3.0% rise.

“The contributors to the increase in real GDP in the fourth quarter were increases in consumer spending and investment. These movements were partly offset by decreases in government spending and exports. Imports, which are a subtraction in the calculation of GDP, decreased,” the BEA said.

Back in London, Diageo ended 3.9% higher and led the FTSE 100 after the Financial Times reported Dave Lewis, who took over as chief executive at the start of this year, is planning major changes to his executive team.

Mr Lewis, who earned a reputation for cost-cutting as chief executive of UK grocer Tesco, wants to change the “fat and happy” culture at brewer and distiller Diageo, the newspaper said, citing “two people familiar with the matter”.

This will include replacing several members of the 14-person executive committee, the people told the FT.

Segro closed up 2.0% after it reported a decline in pre-tax profit for 2025, despite increased revenue, as lower valuation gains offset record rental income.

The London-based property developer reported £560 million in pre-tax profit for 2025, down 12% from £636 million in 2024.

Adjusted pre-tax profit, which strips out property valuations, increased 8.3% to £509 million from £470 million.

The weaker earnings amid the improved top line are owed to smaller realised and unrealised property gains, down 72% at £55 million, compared to £195 million a year earlier.

On the FTSE 250 index, TBC Bank closed up 7.0% as it said a positive final quarter of 2025 helped it reach strong full-year results, allowing for a double-digit increase in its annual dividend.

Pretax profit was 1.67 billion Georgian lari in 2025, up 8.4% from 1.54 billion lari in 2024, as total income before credit loss provisions and expenses rose 20% to 3.39 billion lari from 2.83 billion lari.

Within that, net interest income was 2.35 billion lari in 2025, up 24% from 1.90 billion lari in 2024.

TBC Bank declared a final dividend of 3.87 lari per share for a total dividend for 2025 of 8.87 lari per share, up 10% from 2024 and representing a payout ratio of 35%.

TBC also carried out a 75 million lari share buyback programme last year.

Aston Martin Lagonda shares closed down 1.4% after it issued a profit warning as it noted the impact of “heightened tariffs” in the US.

The Warwickshire-based luxury car maker said it expects to report a gross margin for 2025 of around 29.5%, down from 36.9% in 2024.

Aston Martin also anticipates adjusted earnings before interest and tax “slightly below” the lower end of the analyst expectations of a £184 million loss, widening from a £82.8 million loss.

Looking ahead, Aston Martin said it expects a “material improvement” in its 2026 financial performance.

This expectation is driven by a combination of an enhanced product mix, ongoing benefits from its transformation programme and a “continued disciplined approach to operations”.

On the AIM market, SkinBioTherapeutics closed 8.9% higher.

The stock has fallen 2.0% this week.

The Newcastle Upon Tyne-based life sciences firm said non-executive director Alyson Levett will oversee an independent investigation of the events that led to the departure of Stuart Ashman as chief executive officer.

Ms Levett, who chairs the board’s audit committee, will work with FRP Advisory, which the board has engaged to undertake a “forensic review”.

On Monday, SkinBioTherapeutics said Mr Ashman “misrepresented material information to the board, senior management, auditors and advisors” regarding accrued royalty income reported for the financial year that ended in June last year.

The resulting removal of £770,000 in accrued royalty income will reduce financial 2025 revenue to £3.9 million from the previously reported £4.6 million.

The stock has fallen 19% this week.

Brent oil was slightly lower at 71.33 dollars a barrel on Friday afternoon from 71.71 dollars late on Thursday.

Gold climbed to 5,066.90 dollars an ounce from 5,003.14 dollars.

The biggest risers on the FTSE 100 were Diageo, up 69.0p at 1,850.5p, Antofagasta, up 143.0p at 4,018.0p, Burberry, up 35.5p at 1,210.0p, British American Tobacco, up 97.0p at 4,570.0p, and Lloyds Banking, up 2.0p at 104.0p.

The biggest fallers on the FTSE 100 were BP, down 11.08p at 467.92p, DCC, down 65.0p at 5,135.0p, Associated British Foods, down 18.5p at 1,958.0p, Mondi, down 8.4p at 926.6p, and Convatec, down 1.8p at 228.8p.

On Monday’s global economic data are US factory orders figures and a reading on Germany’s business climate.

On the corporate slate for Monday are full year results from Mony Group, with major results due later in the week from HSBC, Diageo and Rolls-Royce among others.

– Contributed by Alliance News