There’s definitely good news and bad news for the UK in the latest league tables of global economies drawn up by a leading economic consultancy.

Economic patriots will be cheered by calculations which put the UK ahead of France as the world’s fifth biggest economy. On the downside, this appears to be mainly because Britain now includes earnings from drugs and prostitution in its GDP figures, which France as yet does not.

The 2014 economic league table by London-based Cebr Global also concedes that in reality France might still be bigger, given the relatively tiny margins involved. The UK economy is estimated to be worth $2,828bn (£1,818bn) in total, a mere £1bn bigger than the French.

In June, the UK economy received a statistical boost of £65bn after earnings from drugs and the sex trade were included for the first time, under new EU rules.

While it pushed up GDP by almost 5%, economists stressed it was a mere accounting measure and should not be taken as a sign of increased economic vitality. France has yet to take this step.

Britons should enjoy their relatively lofty perch while they can. Apart from being possibly pushed back into sixth by the French next year, India’s economy is forecast to overtake the UK’s as early as 2018. It is now estimated to be the world’s ninth biggest, up from 1oth last year.

Among the losers in this year’s table is Russia, which dropped from eighth to 10th thanks to a weak rouble and low oil price. One oddity of this is that it pushes Italy, hardly undergoing an economic purple patch at the moment, up a place to eighth.

Among the big hitters, the US remains the world’s largest economy by some distance – it is said to be worth $17,528bn, compared with China’s $10,028bn – and Cebr Global predicts the pair will swap places in 2025. By 2030, according to the forecasts, the global top five will be China, US, India, Japan and Brazil, with the UK predicted to be back up to sixth, having just overtaken Germany.

Cebr’s chief executive, Douglas McWilliams, said: “The world economic league table also shows the dramatic changes now taking place in the world’s economic geography, with slow growing European economies falling back and Asian economies, even though their growth is slowing, catching up.”