In 75 fittings across the UK, just six chain-store bra fitters recommended a bra that fitted really well. An appalling 59 of them recommended poorly fitting bras - so Which? can't recommend a single one of the services it tried.

A third of the bras recommended weren't even comfortable. Although fitters should spot problem areas such as bulging cups and loose underbands during the fitting, only around half pointed these out. Cups that were too small, wires that were the wrong shape and wrong back sizes were common.

The worst fitting was from a London branch of Debenhams, where a 'push 'em up, stick 'em out' style moulded bra was recommended to a researcher in her eighties. The bra didn't even fit: the underband was too loose, the breasts spilled out at the front and sides, and the underwire was the wrong shape.

One of the main problems with high street bra-fitting services is that they work on the basis that each woman is one particular bra size, figured out using a tape measure and a formula. In 89 per cent of the visits, researchers were measured and told their size before they even tried on a bra.

In reality, these calculations can be far from accurate; the size that fits best will vary according to style, manufacturer and fabric. To add to the confusion, the formulas vary from one shop to another, meaning a woman who visited more than one bra fitter could be told, as Which?'s researchers were, that she was a range of different sizes*

A good fitting should include some hands-on checks - for example checking whether a wire fits all the way round a breast, checking the tension of the underband, and adjusting shoulder straps. But over a quarter of fitters didn't check the cup, shoulder straps or underbands at all. Fitters at Debenhams were the most hands-off, and those at La Senza were less likely than others to make adjustments to shoulder straps.

On a more personal level, too many fitters failed to put women at ease during a fairly intimate - and pretty strange - experience. Only around half the fitters explained what they were doing, and a few made adjustments in an unnerving silence, without offering any tips or advice.

Some of the advice that was given, meanwhile, was incorrect or just didn't make sense. One Marks & Spencer fitter thoroughly confused a researcher by advising a bra should last for two years - an optimistic estimation as it is - or "four to five years for a normal one"