Britain and France were vying for a the 5th spot when France displaced Britain in the wake of a renewed slump in the pound following the Brexit vote. The pound has fallen by about 14 per cent against the dollar since it hit $1.50 ahead of the referendum result, and has fallen 0.9 per cent against the euro to €1.1656 on Wednesday.
Britain's gross domestic product stood at 1.864 trillion pounds in 2015, according to the last available figures from the International Monetary Fund (IMF).
The fall of the pound against the euro – to the lowest level since 2013 –puts the value of France’s gross domestic product for 2015 slightly ahead of Britain’s according to one measure.
The UK had held the title of being world's fifth largest economy since 2014. France has previously held the title of the world's fifth largest economy until 1997 again losing to Britain. However, it regained the title in 2008 as UK was hit with the global economic crisis in 2008.
What are the economic implications that Britain faces as the pound falls in value?
Analysts expect months of economic and political turmoil which will dwarf the pressure on UK markets following sterling's "Black Wednesday" in 1992 when Britain was forced out of the pre-euro Exchange Rate Mechanism.
Britain's economy would grow more slowly outside the EU than if it stayed in, according to a raft of projections made in the run-up to the referendum by the government, the BoE, think-tanks, international organisations and hundreds of academics. More than £100billion has been wiped off London's FTSE 100 and ratings agency Standard and Poor's warned it would likely downgrade the country's triple A rating. On a lighter note, many UK holidaymakers traveling abroad will pay more for foreign currency as a result of financial turmoil. While household debt has come down from its pre-crisis peak of 150pc of disposable income to around 132pc in the first quarter of 2016, the Bank warned that ratios remained “high by historical and international standards”
While the formal process for Britain to leave the EU has not begun as the ruling Conservative Party seeks to replace Prime Minister David Cameron. Talks about the future of Britain's ties to the EU could take years to complete. The variation in the currency movements are being watched very carefully.