Britain is expected to become the largest Western European economy in 2030 by overtaking Germany, said a research report issued by the Center for Economics and Business Research (CEBR) on Thursday.
The CEBR World Economic League Table report said that Britain is "the West's second best performing economy."
It predicted that Britain would become the world's fifth largest economy in 2018 by overtaking France.
"After that it slips back to 7th place in 2023 and 2028 as India and Brazil overtake."
"But by 2028 the UK economy is forecast to be only 3 percent smaller than the German economy and is likely to overtake Germany to become the largest Western European economy around 2030."
Douglas McWilliams, CEBR chief executive, told The Daily Telegraph that Britain could become even stronger outside the European Union (EU).
"My instinct is that in the short-term, the impact of leaving the EU would undoubtedly be negative," he said, but adding "My suspicion is that over a 15-year period, it would probably be positive."
The report also said slow growth, a weakening currency for some countries would hit the European economies.
"If the Euro broke up, the outlook for German GDP would be much better and the outlook for the other European economies correspondingly worse."
"On the assumption that the Euro holds, Germany drops from the 4th largest economy in 2013 to the 6th largest in 2023 and 2028."
"For France the drop is more precipitous - from 5th in 2013 to 8th in 2018 to 10th in 2023 to 13th in 2028. Similarly Italy drops from 8th in 2013 to 15th in 2028 and Spain from 13th in 2013 to 18th in 2028."
Official figures showed that the British economy grew by 0.8 percent in the third quarter of 2013 from the previous three months.
According to the report, Britain's gross domestic product (GDP) will grow from more than 1.59 trillion pounds in 2013 to 2.6 trillion pounds in 2028.