UK fashion giant Mosaic Fashions, which encompasses Karen Millen, Coast and Whistles, insists that Dunnes Stores has ripped off some of its designs. The company . . . which represents the 'haute' end of the High Street . . . claims that, while copying goes on in the industry, Dunnes Stores purchased its products and commissioned exact copies or almost exact copies, documented in company memos.

Over four days in court, the Miu Miu and Fendi handbags were out in force as the Karen Millen girls eyed up the Dunnes crew every morning to see who was winning in the style stakes (the jury's out on who's got the upper hand, but my money's on Dunnes . . . their witnesses went for subdued sleek while Ian Galvin, chairman of Mosaic Ireland, has overdone it with his silk scarves, patent shoes and pinkie rings).

But make no mistake . . . the real stars of this fashion show are the legal teams. Former Tanaiste Michael McDowell is wielding the measuring tape on behalf of Mosaic Fashions. The one-time minister for justice quite contentedly leafed through photocopies of fashion pages from Marie Claire magazine last week in much the same way as he used to pore over garda crime statistics. Occasionally, he would turn the pictures upside-down and frown, possibly perplexed by this sudden shift from crime scenes to fashion.

McDowell quizzed witnesses on the "faux shrug-over-cami" top that his clients allege Dunnes ripped off, as if he'd been born threading a needle through fabric. He even went so far as to comment on the shirt selection of his opposing counsel, Richard Nesbitt SC. "I was looking at Mr Nesbitt, he's wearing an Oxford stripe, is that right?" he asked witness Helen James, a clothing and accessories designer giving evidence on behalf of Dunnes. She told him he was correct, making him beam even more widely.

But the so-called Rottweiler proved he could still bare his teeth as he insisted, while grilling Ms James, that despite her opinion, there was little difference between his client's top and Dunnes' supposed copy. Not that Nesbitt was to be outshone.

The part-time Arnotts chairman . . . who recently bought out the company following a row with rival shareholders . . . proved he could hold his own. Fashion is in his blood, after all. Technical terminology flowed from his lips and his ensemble, despite being mostly hidden under legal robes, seemed a finer cut than his opposing counsel's attire. Nesbitt's Oxford stripe was certainly a more adventurous choice than McDowell's classic white.

There was plenty of banter between the two eminent legal minds, as well as from Justice Mary Finlay Geoghegan, who was also impeccably turned out. Driving a point home, McDowell insisted that a husband couldn't tell the difference between the Millen striped shirt and the Dunnes' lookalike.

"Even a husband sitting at home wouldn't be able to tell the difference if his wife was wearing them.

He wouldn't dare say they're the same, of course, " he quipped. "We're not dealing with hypothetical husbands, " Geoghegan replied straight-faced but with a glint in her eye, causing McDowell and Nesbitt to laugh out loud.

At the end of the day, though, this fashion stuff is a serious business. Weeks of planning clearly went into deciding which outfit the designers and stylists were wearing each day. The short walk to give evidence seemed far more important than what each witness actually said, judging by the number of craning necks and purposeful strolls, and it served as the main opportunity for the opposing camps to really scope each other out.

Jenine Corletta, a freelance wardrobe stylist called by Dunnes, probably provoked the most interest with her navy Dolce & Gabbana suit and gold bracelets. Designer Helen McAlinden, on behalf of Mosaic, couldn't resist giving her the once-over as she breezed by.

On Tuesday, when the case resumes, legal counsel will present their closing remarks and discerning consumers should pay close attention. If Dunnes is found to have infringed on Mosaic, imitations of designer clothing in all the high-street shops could fast become a thing of the past. "It's hard to know why Mosaic are taking this legal action, they might be doing it for publicity, " observed fashion journalist Ciara Elliott. "Fashion really is a dirty business."