FTSE 100 Slips Amid Oil Price Woes and US-Iran Diplomacy

The FTSE 100 index closed lower on Tuesday, weighed down by weaker oil prices and concerns about UK public finances.

Brent crude fell below $100 a barrel to around $99.39 due to improved supply prospects and Iran's indication that it could reopen the Strait of Hormuz within seven days if the US reduces military pressure and lifts restrictions on Iranian ports.

In contrast, Kingfisher jumped 12% after lifting its full-year profit guidance, while Smiths Group gained 7.5% after stronger-than-expected operating profits and further strategic action.

The UK government's borrowing in August rose to £18.3 billion, around £2.9 billion more than a year earlier, as spending growth outpaced receipts.