Blue chip shares hit an all-time closing high as stocks made gains on the first day of trading after the Christmas break.
The FTSE 100 closed 37 points higher at 7106.08, beating the 7103.98 point mark set in April this year. The FTSE 250 Index also closed 103.2 points higher at 18012.8.
The rally at London's main benchmark was driven by mining companies on hopes of robust US economic growth next year, powered by incoming President Donald Trump's $1tn (£819bn) infrastructure investment programme.
Miners led the blue-chip risers, with BHP Billiton up 54p at 1311.5p and Anglo American 40p higher at 1165.5p.
In the second tier, housebuilder Bovis Homes warned its full-year profit will be lower than expected due to building delays in the run-up to Christmas.
Kent-based Bovis said it suffered "slower-than-expected build production" this month, with completions on around 180 homes set to be delayed into early next year. It now expects to complete between 3,950 and 4,000 homes in 2016.
The FTSE 250 firm, which concentrates on the South of England, said it now expects annual pre-tax profits to range between £160m and £170m, below previous City forecasts of £183m. The company turned in a pre-tax profit of £160.1m in 2015.
Analysts at Numis said it was "disappointing" to reduce forecasts and blamed "company specific factors". It added that the new build housing market remained strong. Numis cut its 2016 pre-tax profit forecast for Bovis by 11% to £165m. Shares in the housebuilder fell 45p to 811p.
Also in the second tier, shares in Sports Direct rose 6.8p to 279.2p after it announced a £112m sale of its Dunlop brand to Japan's Sumitomo Rubber Industries.
The retailer said it did not have the capacity to "develop and manage international brands simultaneously" and needed to prioritise its core UK businesses and relationships with third party brands.
Retail analyst Nick Bubb said the statement could raise investors concern as the retailer owns a number of sports brands. Sports Direct shares have fallen more than 50% this year.