FTSE 100 Index, British benchmark stock market gauge, Wednesday increased by 1.57 percent, or 107.59 points, to 6,945.20.
Britain raised its economy growth forecasts on Wednesday as the country's chancellor of the exchequer George Osborne announced an annual budget statement.
Britain economy growth forecast in 2015 was rose to 2.5 percent and growth in 2016 was expected to reach 2.3 percent.
British unemployment rate in the three-month ended January 2015 was 5.7 percent, the same as the three-month to December 2014, remaining at the lowest level since mid 2008, data showed by the Office for National Statistics (ONS) Wednesday.
The unemployment rate is slightly higher than the market estimation consensus of 5.6 percent.
The nine-member Monetary Policy Committee (MPC) of the Bank of England (BoE) voted unanimously on the holding benchmark interest rate this month, as they keep an cautious eye on strong sterling, according the central bank's meeting minutes published on Wednesday.
Standard Chartered's share price increased by 8.08 percent, topped the gainers of the blue chips. St James's Place, CRH, Royal Mail and Ashtead Group increased by 5.16 percent, 4.98 percent, 3.94 percent and 3.37 percent respectively.
Fresnillo led the top losers of the blue chips with a share price drop of 2.28 percent, followed by Rio Tinto (1.50 percent), Weir Group (0.96 percent), Antofagasta (0.80 percent) and Burberry Group (0.53 percent).
The index has gained 6.78 percent so far this year when measured in U.S. dollar.