Who tops the poll for style?

"She married beneath her. All women do," as the great Oscar Wilde once observed.

So, first let it be known that our three would-be leaders are all very lucky men indeed. Each has married up, at least in terms of attractiveness, each wise enough to select a mate who can be decorative when required, but not so glamorous that she threatens to outshine every pearl that might escape his mouth.

The past few weeks on the election trail must have been trying for the three would-be first ladies, as they attempt to dress the part of supportive but not uppity wife.

Unsurprisingly, all three have shied away from anything too showy or too expensive. There's been barely a handbag seen, not even one from Samantha Cameron's company, Smythson (where the iconic Nancy handbags cost from 795, for the smaller version).

Instead, there have been pieces from tried-and-trusted M&S, mixed in with Zara, Jigsaw and Reiss from SamCam, and Jaeger, LK Bennett and ethical company People Tree from Sarah B.

Each has shown occasional splashes of colour, but in the main, it's been a sensible, neutral colour palette from all three women.

Shoes have provided talking points, however, from SamCam's Converse All-Stars (ironically cool, or just trying too hard to be down with the kids?) to Sarah B's red cork peep-toe wedges (a flash of inspiration or package holiday horrors?).

After a month of campaigning, it should come as no surprise if they start to look jaded.

Contrast Sarah B's chirpy outfit at the start of the campaign (her main picture, right) with the moody black and blue ensemble she wore last weekend.

Compare SamCam's working mum-to-be outfit with the scary Stepford Wives sprigged dress she wore as she gazed adoringly at her husband last Sunday – coupled with Tory plans to reward stay-at-home wives (sorry, partners), perhaps independent working women have cause to be worried?

As for Miriam Clegg's cardigans, they have become bigger and bolder as the campaign has continued – the long red and pink patterned one she wore last weekend was perhaps a knit too far?

SARAH BROWN

With a professional background in public relations, Sarah, 45, obviously knows how to put a best brave face on most situations and has the benefit of being pals with fashionistas including Naomi Campbell.

She has borrowed a trick or two from Michelle Obama, mixing smart with casual and designer with High Street, particularly keen on the non-power cardigan as a great way of covering up without looking too corporate.

She doesn't always pull it off, however (witness her knobbly, unpainted toes at a Hindu temple). A typical pear shape, she looks best in on-the-knee flared skirt.

Anything about the knee, or those too-tight, calf-length pencil shirts she has been wearing, spell disaster for her look. She started the campaign well, but her style has taken a sombre turn in recent days, matching dark tones with a grim, edgy smile.

Campaign highlights: Non-power cardis, nifty macs, stylish haircut, radiant complexion.

Campaign gaffes: Tight pencil skirts and those un-pedicured feet.

SAMANTHA CAMERON

Tall and slender, and the youngest of the three contenders at 39, Samantha has had conservative fashion watchers drooling with admiration and envy.

As the artistic director of luxury stationer and leather goods firm Smythson of Bond Street, she ought to be the most fashion-savvy of the three. She certainly has the best wifely accessory – a neat pregnancy bump.

The daughter of a baronet, SamCam sometimes betrays her privileged upbringing in a style that veers alarmingly towards 1980s drippy Sloane Ranger (witness her flat ballerina pumps and ankle-skimming trousers).

For the campaign she has wisely steered clear of expensive designer clothes and accessories opting instead for posh High Street labels such as Jigsaw and Reiss. She would benefit from a stronger, more directional haircut.

Campaign highlights: Stylish scarves and smart jackets, great smile.

Campaign gaffes: Those Converse trainers (there's a teenager still looking for those).

MIRIAM CLEGG

Probably the most naturally beautiful of the three women, Miriam, 42, is known as Miriam Gonzalez Durantez in her professional life as an international lawyer.

Rather oddly, for a high-powered Spanish career women, when she is not in her working wardrobe of black shift dresses and jackets, Miriam often dresses like a frumpy, English, middle-class school-run mum, in jeans and voluminous cardis (great boots, though), and yet, with characteristic continental flair, she somehow makes it all look chic, elegant and oh so easy.

It must be a little galling to the other two wives that she barely makes an appearance, and doesn't seem to make much of an effort when she does, yet she still manages to look stunning and effortlessly stylish. Mind you, that red and pink long cardi she wore last weekend was in danger of wearing her, rather than the other way around. Enough with the cardigans, Miriam.

Campaign highlights: Lovely shiny hair, flashing eyes, an independent, spirited demeanour.

Campaign gaffes: Over-sized jackets and cardigans – Miriam is drowning her frame in ill-fitting clothes.