The BBC executive Alan Yentob hit out at the corporation's critics and attacked ministers for trying to interfere in its affairs.
Mr Yentob, the BBC creative director, told London's Evening Standard that expenses claimed by the corporation's top brass were reasonable, and there was no need for a "collective mea culpa".
Figures released at the end of June showed that high-level managers claimed £400,000 on expenses over the past three years, on champagne, cigars, flowers, cosmetics, food hampers and a Doctor Who action figure. Mr Yentob charged the licence-fee payer nearly £1,600 for an "executive Christmas dinner" and £160 for a lunch to discuss Nigella Lawson's contract, which he now says the chef did not even attend.
Mr Yentob said entertaining in such a way brought in more business.
The BBC was criticised after it emerged that radio and TV station chiefs showered celebrities with gifts and "thank you" lunches.
Mr Yentob, whose contract is worth up to £340,000 a year, insisted the spending was a reasonable way of holding on to big names, to benefit the corporation. But he said expenses were likely to be reined in: "From now on, and I don't just mean because of the exposure in the papers, the BBC is going to be tougher and meaner."