The UK economy is now larger than before the financial crisis in 2008 according to ONS quarterly data released today.
It comes as the IMF predicted Britain will be the fastest-growing advanced economy in 2014.
Lib Dem Treasury Minister Danny Alexander has said it vindicated the party's decision to form the coalition in 2010.
Commenting, Danny Alexander said: "Today we are passing a major milestone on the long road back to full recovery. There is still a long way to go but Britain has recovered the economic ground lost under Labour and is forging ahead.
"The main reason that we stepped forward to form the coalition was to sort out Labour's economic mess and rebuild a stronger economy and a fairer society for the future.
"By forming the coalition we gave the country a long term economic recovery plan based on Liberal Democrat values and policies and the stability to see it through.
"Because we have taken the difficult decisions to stick to that plan we are now seeing strengthening growth and the creation of record numbers of jobs.
"Growth and job creation, combined with rising business investment is the only way to deliver the higher living standards that the families of Britain deserve."