Tony Blair has spoken out about the stress of being prime minister in a "day in the life" documentary.
Put together by the prime minister's aides and aired on his website, the video claims to provide the public with "a rare glimpse" into Mr Blair's life.
In it he says nothing prepared him for the stress and hard work of the job or being under such constant scrutiny.
He adds that he works such long hours that he is probably breaking "some directive or other".
He tells the camera: "There is never a typical day, all days are different.
"There are any number of different issues that can come up in a day and then you can always have something completely unexpected that translates one type of day into a completely different one.
"The important thing is, is to be able to compartmentalise, to be able to switch from one subject into another."
Speaking about the demands of his job Mr Blair says that "being leader of the opposition does not prepare you quite adequately for the difficulty of doing the prime minister's job".
"It's completely a different order of stress, challenge, pressure," he says.
BBC political correspondent Jo Coburn says these comments are a "pointed message" to Mr Blair's new rival, David Cameron, who has been the focus of media attention since his election as Conservative leader.
'Nooks and crannies'
Mr Blair admits he received some helpful guidance from a previous prime minister.
"I remember Mrs Thatcher once saying to me that the most important thing about prime minister's questions is that it gave you the opportunity to know exactly what was going on in all the different nooks and crannies of government," he says.
The three-and-a-half minute video is one of a series of films which can be viewed on the prime minister's website and follows a new trend of informal behind-the-scenes documentaries about political leaders.
For Christmas the White House released a film about George Bush seen from the point of view of the presidential Scottish Terriers, Miss Beazley and Barney.
The 10-minute video was available on the White House website.