Greece suddenly found itself 25 per cent richer on Thursday after a surprise upward revision of its gross domestic product, the fruit of a change to national accounts designed to capture better a fast-growing service sector – including parts of the black economy such as prostitution and money laundering.

The country’s newfound wealth raised eyebrows in Brussels, because it means Greece will find it easier to bring its budget deficit below the European Union’s 3 per cent of GDP ceiling.