The CEBR World Economic League Table report said that Britain is "the West's second best performing economy", media reported. "My suspicion is that over a 15-year period, it would probably be positive," he added. (Agencies)
It predicted that Britain would become the world's fifth largest economy in 2018 by overtaking France.
"After that it slips back to seventh place in 2023 and 2028 as India and Brazil overtake. But by 2028, the UK economy is forecast to be only three percent smaller than the German economy and is likely to overtake Germany to become the largest Western European economy around 2030," it said.
Douglas McWilliams, CEBR chief executive, said 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.
The report also said that 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 fourth largest economy in 2013 to the sixth largest in 2023 and 2028," the report said.
"For France the drop is more precipitous from fifth in 2013 to eighth in 2018 to tenth in 2023 to 13th in 2028. Similarly, Italy drops from eighth in 2013 to 15th in 2028 and Spain from 13th in 2013 to 18th in 2028," it added.
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.
The CEBR World Economic League Table report said that Britain is "the West's second best performing economy", media reported.
"My suspicion is that over a 15-year period, it would probably be positive," he added.