The blue-chip FTSE 100 gained 0.6% by 0830 GMT, while the more domestically focused FTSE 250 mid-cap index rose 0.6%.

Tesco lost 1.3% after Britain's biggest retailer kept its full-year guidance, though the company's chief executive said inflation may have not peaked "just yet."

Strong Christmas sales did little to aid Marks & Spencer shares, which fell 1.3%, as the retailer remained cautious about "clear macro-economic headwinds ahead and underlying cost pressures."

Investors keenly await U.S. inflation data later in the day, a critical pit stop before the U.S. Federal Reserve's February rate-hike decision.

Materials stocks took an early lead, with industrial and precious metal miners rising 0.5% and 1.1%, respectively. [MET/L] [GOL/]

Centrica climbed to the top of FTSE 100, jumping 5.5% after the British Gas owner raised its full-year earnings forecast.

Halfords slumped 19.4% after the motoring and cycling parts retailer trimmed its annual profit outlook.

(Reporting by Shashwat Chauhan in Bengaluru; Editing by Subhranshu Sahu)