An aide says the prime minister's fury has seen him hurl pens and a stapler as well as shoving a printer off a desk

What happens when Gordon Brown gets angry? The laser printer gets it

I've read plenty of stories about Gordon Brown's rage before (normally involving mobile phones or a stapler), but I had never heard any anecdotes about a laser printer getting it in the neck until today.

This comes from Bloomberg, a pretty reliable news source:

The strain shows, say current and former Brown aides: among other things, it has inflamed a temper that has always been the subject of gallows humour among those who work with him. The prime minister, 58, has hurled pens and even a stapler at aides, according to one; he also says he once saw the leader of Britain's 61 million people shove a laser printer off a desk in a rage. Another aide was warned to watch out for "flying Nokias" when he joined Brown's team.

The tale crops up in a lengthy piece about Brown that also contains a description of how the prime minister's aides have apparently learned to cope with his behaviour: they've invented the "news sandwich".

One staffer says a colleague developed a technique called a "news sandwich" – first telling the prime minister about a recent piece of good coverage before delivering bad news, and then moving quickly to tell him about something good coming soon.

Update, 11.30am: I've just come back from the daily Downing Street briefing for lobby journalists. After 10 minutes on GDP figures, Gurkhas, MPs' expenses etc, someone had to lower the tone and ask about this – and I'm afraid it was me.

This is what the prime minister's spokesman said in reply:

I think it is the sort of unsubstantiated, unsourced nonsense that you would expect to read in Sunday newspapers, not on the supposedly respectable financial wire services.

There was then a lovely moment of humour when someone else asked: "But is it untrue, though?"

The spokesman said it was "the sort of nonsense that you might expect to read in diary columns" and "not an account that I recognise".

But he did not actually say it was untrue.