YAHOO fosters the impression that it is an open and friendly company, in keeping with the consumer brand that is familiar to hundreds of millions of internet users.

Brad Garlinghouse, a senior vice-president at the world’s most-trafficked website, seems to have decided to test the limits of this openness to the point of destruction.

In a leaked internal memo now widely discussed on the internet, Garlinghouse recently told colleagues that Yahoo had become a poorly managed mess — with too many under- motivated employees working on too many competing products.

Yahoo was slow-moving and indecisive, he said, “held hostage by our analysis paralysis”. Management accountability was fragmented, and there was “massive redundancy” — “For far too many employees, there is another person with dramatically similar and overlapping responsibilities.”

In the most memorable passage of what has become known as the Peanut Butter Manifesto, Garlinghouse alleges that Yahoo is spreading its efforts too thinly.

“We want to do everything and be everything — to everyone. We’ve known this for years, talk about it incessantly, but do nothing to fundamentally address it.

“I’ve heard our strategy described as spreading peanut butter across the myriad opportunities that continue to evolve in the online world. The result: a thin layer of investment spread across everything we do and thus we focus on nothing in particular.

“I hate peanut butter. We all should.”

It is hard to read this as anything other than a wholesale condemnation of the leadership of Terry Semel, the Yahoo chief executive who is already struggling with a share price that has fallen by more than 25% this year. Yahoo has been undermined by weak advertising revenues, a delay with a crucial new ad system — and the inexorable sense that its great rival Google is pulling away from it.

What was most striking was not so much the criticisms themselves, many of which have been raised before, but the identity of the person making them. Garlinghouse is responsible for some of Yahoo’s most important properties, including Yahoo Mail, the world’s favourite webmail service; the Yahoo.com home page; Yahoo Messenger, the widely used instant-messaging service; and My Yahoo, the most popular personalised start page.

In recent months, Yahoo’s executives have batted away the criticisms, insisting that the stock price and financial commentators are ignoring the strong progress it is making with a number of new products.

Most notably, Yahoo Answers, which allows people to pose questions to internet users, has attracted more than 60m users since its launch last December. Traffic to photo-sharing site Flickr has also grown more than 10 times since it was acquired for $30m (£15.5m) last year.

Earlier this month in San Francisco, The Sunday Times spoke to Ash Patel, Yahoo’s chief product officer. “People look at the financial results and don’t always understand the full picture,” he said. “Yahoo’s core business is audience. We are innovating with great products and doing really well. Innovation and creativity is very much alive at Yahoo.