The changes to the BBC's strategy to be outlined today will be "significant", according to media commentator Steve Hewlett.
Interviewed by John Humphrys, Mr Hewlett said that, if speculation was correct, he could not think of another time in the corporation's history when it had voluntarily given something up.
In a wide-ranging report on the BBC's future, John Humphrys found a wide range of views on its role.
Independent producer Peter Bazalgette, the man who brought Big Brother to UK television, complained that BBC Radio 1 and 2 "crush the commercial radio sector"
But the former BBC chairman Sir Christopher Bland warned against deep cuts in the corporation's output, adding "less comprehensive means worse".
And reacting to a report which indicates that investment in BBC content has dropped by 10% in recent years, BBC Trust member Dame Patricia Hodgson agreed that the aim of the strategy change is to invest in core high quality content.
The BBC's director general Mark Thompson is to announce the results of the BBC's strategy review this morning, amid press speculation that Radio 6, the BBC's Asian Network and half the corporation's website may be closed.