Britain's economic growth is expected to be close to zero in 2012, staying in mild recession, a report on global economic forecast issued by a leading thinktank in Britain said on Friday.

The National Institute of Economic and Social Research (NIESR) said it expected a recession in euro zone and Britain as well in the first half of 2012.

It forecasted a 2-percent growth for Britain in 2013, saying the persistent weakness in the economy was "unprecedented".

NIESR said Britain's unemployment rate will rise from its current 8.3 percent to almost 9 percent by the end of this year, bringing about "permanent damage to Britain's productive capacity."

The latest official figures showed Britain's economy shrunk by 0.2 percent in the first quarter of this year, indicating that the country has slipped back into recession, as it has witnessed two consecutive quarters of negative growth.