The levers of power must deliver a few domestic perks after all - a Ford Galaxy and driver to take the children to school, a cook to rustle up family suppers, a housekeeper to organise the shopping. But they don't. Contrary to popular perception, there seem to be no free rides for the family living at Number 11 - because Number 10 is too small for the family and they have swapped the living quarters with Gordon Brown.
"It's not hot- and cold-running footmen under the chandeliers," says Carol Thatcher, whose own working mother was so busy that when Carol was invited home for dinner: "I took the dinner."
The Prime Minister's residence is certainly split by a metaphorical green baize door (the actual door is white): downstairs a dining room seating more than 60, a kitchen accustomed to providing banquets at the drop of a hat and a fleet of cleaners. Upstairs - nothing.
Well, nothing in the way of help, although Mary Wilson found quite a lot of hindrance during her time at Number 10. "One of her complaints was that there always seemed to be someone from the Ministry of Works coming in to wind the clocks," says Joe Haines, Harold Wilson's press secretary. "They'd just walk in - it wasn't locked. Or private secretaries would walk in to see the Prime Minister. There was no privacy."
This prompted the Wilsons to move to Lord North Street, leaving Number 10's bedrooms to those - like Mr Haines - who were often tied to their desks. As they rarely had time to go out for lunch, Mr Haines and his colleagues at Number 10 pooled their resources to hire a cook; the Wilsons did the same. Margaret Thatcher, however, didn't bother, Carol says, "because they ate so rarely in the flat. They were quite happy to have egg on toast." But while Mr and Mrs Blair are sure to be dining out all too often, someone will have to look after the children.
In the past, the Prime Minister has done his share. According to his wife, "He's very good at polishing the shoes and has been known to cook a meal - if I am late in, he cooks. I wouldn't say he is intimate with our washing machine, but he knows where it is."
There will be no time for that in his new life, although Mrs Blair should take heed of Therese Lawson's memories of moving in to Number 11.
"I had to find the sheets and make all the beds up myself. It is a vast place and it was really quite an effort to keep everything in order. I found that the hoovering, especially, took ages," she wrote. "There are several loos and bathrooms - seven to be precise - and one of my pieces of advice to Mrs Blair would be to buy her loo paper in bulk or even to order it in."
The nation will probably know if Cherie (or her nanny) follows this advice, since there is no convenient back entrance to Number 11. "I used to take the shopping baskets in with lettuces overflowing," Carol Thatcher says, while Mrs Lawson, who hired domestic staff, felt that she was always on display and needed to dress up before going shopping.
There are no handy corner shops in Downing Street, but on the other hand, Carol says, "If there's no milk you can probably nip downstairs and see if you can cadge some off the police." And there are no freebies.
"If Harold Wilson invited me up for a drink at night, which he often did, Mr Wilson had to pay for the drink," Joe Haines says, adding that Mr Blair will also be charged for non-official trips in any of the Downing Street cars, including the celebrated new addition, the Ford Galaxy people- mover.
There will be no school runs carried out by government drivers, though it will be pretty easy for Mr Blair to continue his habit of taking Euan, 13, to the Underground each morning - Westminster tube station is just around the corner.
Norma Major, a born housewife and well-qualified to get Number 10 running smoothly, chose instead to live at the family home in John Major's Huntingdon constituency. Mrs Blair had no such thoughts, apparently, saying that "wherever Tony goes, we are going too. The most important thing is to keep the family together. We want to keep life as normal as possible."
Mrs Blair, daughter of the erratic sitcom star Tony Booth, knows something about the horrors of growing up with a famous parent, and is determined to shield her children from the media. This might seem easier to achieve in Islington than in Westminster, but if the family had stayed at home in Richmond Crescent, the Prime Minister would hardly ever have seen his children.
Harold Macmillan famously put up notices for his grandchildren: "No roller- skating in the corridors today. Cabinet meeting." But it is rather cheering to think that ambitious politicos and civil servants might be disturbed by the occasional childish shriek.
They might even be inspired to legislate on behalf of working mothers by the sight of Mrs Blair's balancing actn