The London market surged in afternoon trading after rising commodity prices lifted heavyweight oil and mining stocks.
The FTSE 100 Index added 92.6 points to 6802.8, after oil, copper and aluminium prices all made gains. The FTSE 250 Index rose 11.5 points to 17863.4.
Anglo American was up more than 6%, or 50.3p to 864.7p, Glencore lifted 9.2p to 194.2p, while BP was 8.6p higher at 429p.
Spreadex financial analyst Connor Campbell said: "It was an undoubtedly strong start to the week for the FTSE, which has maintained its near 100 point rise since the session began."
In the second tier shares in outsourcing group Mitie sunk by a quarter after it cut its profit outlook amid uncertainty over the UK's decision to leave the EU and other "economic pressures".
Mitie said its profits would be "materially below" its full-year expectations as a result of challenges it faced. Shares fell 70p to 199p.
In afternoon trading the biggest risers in the FTSE 100 Index were Anglo American (+50.3p to 864.7p), Glencore (+9.2p to 194.2p), BHP Billiton (+35.4p to 1021.5p), Standard Chartered (+21.3p to 628.4p) and Rio Tinto (+77p to 2356.5p).
The biggest fallers in the FTSE 100 Index were Shire (-27p to 5068p), AstraZeneca (-22p to 5073p), SABMiller (-5p to 4435p), Intu Properties (-0.3p to 286.4p) and Royal Mail (-0.5p to 516p).
In afternoon trading the biggest risers in the FTSE 250 Index were Centamin (+8p to 142.7p), Vedanta Resources (+27.2p to 522.5p), Hunting (+21.8p to 442p), Evraz (+7p to 145p) and Petrofac (+29p to 825.5p).
The biggest fallers in the FTSE 250 Index were Mitie (-70p to 199p), Dairy Crest (-31.5p to 636.5p), JRP Group (-5p to 115.2p), IP Group (-7.1p to 185.3p) and Millennium & Copthorne Hotels (-16.5p to 445.2p).