Blue chip shares gained ground, shrugging off falling energy stocks after the Conservative Party vowed to cap power prices if they won the next election.
Prime Minister Theresa May said she is "fed up with rip-off energy prices" and will cap expensive standard variable tariffs – the most common rate paid by households – if her party wins the next election.
The FTSE 100 Index lifted 49.6 points to 7350.4 in afternoon trading, with miners on the front foot despite household power supplies weighing on the market.
Rising commodity prices lifted such heavyweight stocks such Glencore and BHP Billiton by more than 2% each.
But proposals to cap standard variable energy tariffs, which are on average 11% higher than other energy bills, sent British Gas owner Centrica down by more than 1%, while rival SSE slipped by 0.6%.
IG chief market analyst Chris Beauchamp said: "Such a move is emblematic of the Conservative party's more interventionist stance. It will start with energy companies, but some will be wondering whether other sectors will come under pressure as well."
The biggest afternoon risers in the FTSE 100 Index were WPP (+37p to 1718p), Johnson Matthey (+67p to 3156p), Glencore (+6.2p to 290.6p), BHP Billiton (+22.5p to 1147.5p) and Rolls-Royce (+17p to 867.5p).
The biggest afternoon fallers in the FTSE 100 Index were Micro Focus (-176p to 2463p), Centrica (-2.6p to 199.8p), GKN (-3.7p to 355.3p), Royal Bank of Scotland (-2.5p to 264.1p), Hikma Pharmaceuticals (-12p to 1977p).
The biggest afternoon risers in the FTSE 250 Index were Ferrexpo (+7.8p to 158.2p), Euromoney Institutional Investor (+40p to 1075p), Paysafe Group (+17p to 479.4p), Paragon Group (+16p to 487.6p) and Millennium & Copthorne Hotels (+13p to 460.5p).
The biggest afternoon fallers in the FTSE 250 Index were Travis Perkins (-56p to 1640p), Allied Minds (-5p to 148.6p), Nostrum Oil & Gas (-11p to 435.3p), Hastings Group (-6.4p to 303.1p) and Card Factory (-6.5p to 319p).