The UK is on course to become Europe's largest economy within two decades, overtaking France and Germany, according to a new report.

The think tank Centre for Economics and Business Research (CEBR) predicts the UK's GDP will first move to fifth place ahead of France by 2018 before leapfrogging Germany around 2030.

However, despite being forecast to be the second most successful of the Western economies after the US, it will fall behind the accelerating economies of India and Brazil.

"Germany is forecast to lose its position as the largest Western European economy to the UK around 2030 because of the UK's faster population growth and lesser dependence on the other European economies," the report said.

But added: "If the euro were to break up, Germany's outlook would be much better. A Deutsche Mark-based Germany certainly would not be overtaken by the UK for many years if ever."

Douglas McWilliams, the CEBR's chief executive, said that Britain could become even stronger outside the European Union.

"My instinct is that in the short term, the impact of leaving the EU would undoubtedly be negative," he said.

"My suspicion is that over a 15-year period, it would probably be positive."

It added that a factor driving the UK's move ahead of Germany are the assumption of a falling value for the euro, Germany's falling population and the UK's rising population.

The gap between the two countries will fall from almost £610 billion in 2013 to just £183 billion in five years.

The UK's GDP will grow from more than £1.59 trillion in 2013 to £2.6 trillion in 2028, compared to China which is predicted to be in top position with a GDP of more than £20.5 trillion, ahead of the US with an estimated £19.7 trillion

Japan will fall from its steady position in the global league of third to fourth by 2028, overtaken by India and followed by Brazil, Germany and the UK.