The UK's economy is set to overtake that of France by 2020 to become the second largest in Europe, according to forecasts by consultancy firm PwC.
It says the UK's value is aided by the strength of the pound against the dollar compared with that of euro, together with falling unemployment.
But it says the UK lags behind in areas including education, investment, trade deficits and income inequality.
Germany comes top in Europe and fourth globally after the US, China and Japan.
India is set to overtake the UK by 2030, also rising above Germany and Japan to become the world's third largest economy.
Currently, the UK economy is worth £1.65 trillion ($2.83 trillion), while the French economy is valued at £1.68 trillion ($2.89 trillion).
'Strengths to build on'
John Hawksworth, chief economist at PwC, said: "The UK has noted strengths in areas such as political, legal and regulatory institutions, including ease of doing business and communications technology.
"The UK also scores relatively well on some economic variables such as unemployment and its relative growth and inflation performance also improved in 2013, which looks set to continue in 2014."
He added: "So the UK has clear strengths to build on, but also some underlying weaknesses to address even given its recent relatively strong economic recovery."