On the contrary, the state-owned investment vehicles offer relatively cheap finance and can be credited with ‘saving the banking system of the West’ last winter, claims Professor William Megginson of the University of Oklahoma.

Megginson adds: ‘It’s no overstatement. SWFs poured in huge amounts of liquidity when financial institutions were in serious trouble over the Christmas period. They might have expected gratitude, but ironically hostility towards them [based on suspicion of their motives] has intensified.’

SWFs from regions including the Middle East, China and Singapore have huge resources – $2.9 trillion (£1.5 trillion) according to an estimate from Morgan Stanley. However, they are dwarfed by pension funds, which have over $20 trillion under management, and mutual funds with some $19 trillion, according to Megginson.

He adds that, until now, SWFs have never invested to achieve political ends. ‘As ever, the investor has far more to risk from the behaviour of the target country than vice versa,’ he states.

Pete Hahn, a former banker and London-based academic, says that the biggest threat posed by SWFs is not that they will exert an unwelcome influence, but the reverse.

‘A large sovereign investor is the bad board’s best friend. It allows the board to do whatever they want,’ he states.

According to Hahn, ‘silent’ investors who hold large blocks of shares for long periods will lead to mediocrity in the management of investee companies. Their holdings are also hard to trade because of their size, and sometimes have to be sold at a discount.

Megginson and Hahn were speaking at Cass Business School in London.