Martin Broomer knows what it's like to be King Canute. For the past six weeks he's been overseeing seaside activities in Biarritz , allowing journalists from all over the world to warm the tyres of the new S-Type Jaguar. And everyone who went was only asked to agree to one stipulation: don't report on it before March 24.

While Mr Broomer eyed the lower end of the automotive rag trade with suspician, a deft attack came from the quarter he'd least expected. It wasn't the Ohio Observer, or the Falmouth Packet, but the Financial Times which went to press.

At Wheels, we'd been obediently sitting on our story for weeks, but given that Autocar, Auto Express, and the Sunday Times, and probably the Falmouth Packet, have followed the FT's line, we thought we'd join the tide.

The charter plane had Jaguar's leaping mascot emblazoned down its side, the in-flight meal included Jaguar mint chocolates and, as I nodded off, I rested my face against a Jaguar antimacassar.

In the evening, I resumed my nap during a seminar, regaining consciousness to note such vitals as the car's cosmetic beads on all closures and its limits of tooling feasibility. The omens were not promising.

Then I drove it and saw the light. The new S-Type is automotive sex. For size, price and spec, it sells against the likeable likes of BMW's 5 Series and the Burgermeister Merc E-class. But it is more than the sum of its rivals' parts.

Even the most trenchant German car fanatic will buckle in this car's presence. It might be helped by favourable whole-life costs, pence-per-mile running figures and tax liability, but it all boils down to one fact: this car is just so good you want to eat it.

From being a lover of hard-shoulder dramas in the late 80s, Jaguar has spent the last decade putting things right, investing to a level of build quality and durability worthy of its heritage. The latest XJ saloon was no revolution, but it is Samsonite-solid. Next to it, the new XK coupe has proved such value it has helped Jaguar to its best-ever annual sales.

So when Jaguar resurrected its S badge, last seen in 1963, it had done the homework. The key car has a new 3.0 litre V6 engine. The first car I tested, though, was the destroyer - sorry, flagship - four litre. With a V8 in charge, this S-Type has enough power to call its handling potential into question. In other words, if you rant it round bends, you'll probably be in a tangle, even with the standard dynamic stability control and yaw-rate sensors.

Returning to the main seller, I found a better balance. For a spirited performance, the smaller-engined car is more rewarding, as the power is finely matched to the suspension. If this doesn't excite you, check your pulse.

Whatever you choose, though, it won't have the chauffeurial waft of an XJ. True, the S-Type is silky in a straight line, but it's a geezer's getaway on a mountain road.

Because the auto box is so responsive, opting for the 3.0-litre manual seems like unnecessary hard work. The other good bit is inside. Available toys will include voice-activation for the air con, phone and stereo.

Best is last. As tarmac decoration goes, the S-Type makes rivals execs look dull. On test, the rippled bonnet attracted so much attention that my co-driver wondered if we hadn't perhaps scooped up some wildlife.

You'd think the French would hate a car whose name they can't pronounce but they can't keep their eyes off it. Neither could I. It all left me completely awake, and sure of one thing: Jaguar has not landed in the medium saloon market, it has annexed it.

• The S-Type is on sale now and prices start at £28,300 for the 3.0 V6 manual. The auto V6 version costs £33,150 and the 4.0 V8 £37,610.