PricewaterhouseCoopers, KPMG, Ernst & Young and Deloitte have shed one in five Scottish staff in the past two years.

More than 500 fee-earners have left their jobs in Scotland since 2001.

And entrants have also been hit hard; trainee numbers have been slashed by a third.

PwC alone has reduced the number of people it employs in Scotland by 250 since 2001.

It has reduced its Scottish payroll by a quarter and KPMG's numbers are down by 20%.

The research may be seen as a sign of a weakening Scottish economy.

And the dearth of corporate transactions in the £10m-plus bracket is thought to have hit the big accountancy firms hard.

The research was carried out by CA magazine, the journal of the Institute of Chartered Accountants of Scotland.