Perhaps the question is not who would want to own the canary yellow frock worn by Margaret Thatcher as she stood smiling alongside Ted Heath on the 1975 Tory conference stage. Maybe it should be: who on Earth wouldn't?

Or her fetching gold and silver lamé cocktail ensemble? Or an elegant blush pink wool suit with gilt basket-work buttons over a co-ordinating salmon-pink chiffon blouse that she wore while being grilled about moisturiser by Sue MacGregor in 1971?

"We have had some interest," said Nicolas Martineau of Christie's as he explained why the auction house is selling seven Thatcher outfits from the early 1970s. "People who are interested in Mrs Thatcher and people who are interested in fashion."

The clothes are lots in Christie's "London sale" on Monday, which is the auction house's way of celebrating the Jubilee, the Olympics and the Paralympics. "We've had London sales in the past but they have been very different and much more focused on fine art," said Martineau. "We wanted it to be fun and eclectic. We didn't want just pictures – we wanted some whacky stuff as well."

The dresses show how Thatcher was "the ultimate power dresser", said Martineau. "She was very aware of the power of television and the power it could have and she dressed accordingly."

All the dresses were made for her when she was education minister – or her "milk snatcher" years as the Christie's catalogue omits to say – and each has an interesting story to it.

The pink wool suit, for example, was worn during an interview with MacGregor for a 1971 edition of the documentary series Analysis which investigated why women feel they have to use cosmetics. For Thatcher the reason was simple: "I have a very, very dry skin, almost like sandpaper," she revealed. "And central heating doesn't help."

All the dresses have been given estimates of £1,000-£1,500.

The sale is unquestionably wide-ranging, featuring fine art such as an Edward Seago painting of Hyde Park Corner and an atmospheric view of Southwark Bridge from Blackfriars by John Atkinson Grimshaw; photographs by Terry O'Neill and Norman Parkinson; Tube and street signs; and original posters including one promoting The Clash's 1979 album London Calling.

Most of the lots would fit in your living room but more room will be needed for the full-scale aluminium replica of Eros (estimate £150,000-£250,000) and the 1966 RML Leyland AEC Routemaster double decker bus which Christie's parked outside its South Kensington saleroom – yours for perhaps £20,000-£30,000.