Back in February, at the annual mobile phone industry shindig 3GSM World Congress in Cannes, a representative from Motorola told me that in January and February the fastest selling mobile phone in the UK was the Motorola A835 3G handset.

I took this with a huge pinch of salt. I knew the A835 to be a bulky, rather industrial-looking handset sold exclusively through 3G network Three. Sure, there were signs of a mini revival of interest in 3G handsets. But the A835 outselling Nokia and Sharp seemed highly improbable.

Earlier this week Charles Dunstone CEO of the Carphone Warehouse released figures which showed that the man from Motorola might not have been embellishing the facts as much as I'd thought.

In reporting a pre-tax profit of £76m, up 33.8 per cent, for the year ended 27 March 2004, Dunstone cited "the rapid increase in the volume of our 3G connections since the start of 2004" as a major boost to the retailer. He added that 3G connections and handsets currently make up 25 per cent of Carphone Warehouse post-pay sales, a massive increase from just five per cent in January.

With such positive signs coming from the UK's leading phone retailer you would have thought that the next company expected to launch its 3G services in the UK, Vodafone, would be desperate to gets it handsets to the stores.

Yet, strangely, while Vodafone has announced its consumer 3G services in Germany, Spain, Portugal and Italy, it has kept rather quiet about its plans for the UK. The awful irony for Vodafone, and indeed rivals Orange, T-Mobile and O2, is that when it does launch consumer 3G in the UK, it could have its work cut out competing with Three.

Let's not be under any illusions. So far Three's empire has been built on its ultra competitive pricing strategy for its voice calls - not on consumer demand for its advanced 3G applications.

It would be a huge gamble for Vodafone, or its rivals, to offer similar prices on its 3G services bearing in mind the backlash it will face from customers who will most likely be paying more on GPRS.

So if competing on price is a non-starter, surely Vodafone with its worldwide network, can deliver the most desirable 3G handsets.

Not so. In its other European territories Vodafone's hero 3G handset is the Samsung Z105. Compared with the Beckham-approved GX30 mega pixel camera phone it looks like a relic from a previous era. It isn't a bad phone yet it is still much larger and less well featured than its rivals from Three.

And while Three's early handsets were notoriously large, unreliable and battery hungry, now its portfolio of phones looks quite impressive. Carphone Warehouse was reported to have been selling in the region of 10,000 of Nokia's 3G handsets - the unusual tear-shaped 7600 - per week. Newer models from NEC have been well received while the latest handset, LG's 8110, is the first 3G mobile that's around the same size as a standard GPRS phone.

Vodafone also can't compete with Three in terms of its network. Earlier in the year it promised 60% coverage of the UK population by autumn. But just like Three, that network is almost certainly going to take a year or so to start functioning in a way that consumer would expect it too.

As many who have used Vodafone's 3G card for laptops have discovered, its 3G network works well when it works, but a 3G signal isn't always available in even in places where it should be strong such as central London.

So that leaves content as Vodafone's last potential trump card. Optimists in the industry have talked excitedly about a re-branding of its Vodafone Live! service complete with added video applications. But does anyone really know what sort of 3G content users actually want anyway?

Vodafone's best bet has to be to tap into the football fan market, where it has wrapped up the right to stream Premiership goals to handsets minutes after they have scored.

Yet while this could draw a number of both hardcore and armchair supporters, the downside for Vodafone is that Three has inked a similar deal and is likely to offer an identical service.

Another possibility for Vodafone in the UK would be to follow its Italian sister network and offer clips from TV programmes. Yet, judging by Three's experience in its video download/streaming service, there doesn't seem to be a huge demand for this type of feature. Besides, Three could quite easily offer a similar service if it thought it were a real money-spinner.

Vodafone has also tied up a deal with Sony to offer music video and enhanced ringtones. But it has so far not committed to offering downloading of music tracks over the air direct to mobile phones like its rival O2.

That pretty much leaves person-to-person video calling as its supposed killer application for 3G. Yet, other than grandparents anxious to have raspberries blown at them by their offspring's toddlers, demand for video calling seems pretty much non-existent.

In short, unless the company has some amazing rabbit to pull out of its hat, it seems that Vodafone has no really compelling reasons to present to consumers to upgrade to 3G.

Its only card appears to be the brand itself. The subliminal message has to be that "while an upstart network (Three) offered you limited 3G services, only a trusted established network like us (Vodafone) can deliver it properly."

The trouble is if Vodafone does botch the launch its brand may take a knock.

Perhaps Vodafone is going to take a low-key approach and wait until next year when its network is fully formed and all its glitches ironed out before it really takes Three. Then again, that was the reason phone industry analysts gave for the cancellation of its planned 3G launch for summer 2003.

Although Three has enjoyed a strong start to 2004, it is still way off spending the enormous sums of money Hutchison invested in Three in the first place. It is a sign of how the company is still perceived that last week - when rumours flooded the business community that Hutchison were going to sell the business - the news was not only take seriously, but forced a strongly-worded denial of the rumours from the company's chief executive.

I am sure in the long run 3G services will establish themselves. The handsets will become more desirable, the networks more efficient and someone will come up with a killer application (maybe push-to-talk?) for 3G.

Until then, selling 3G to consumers without the carrot of cheap voice calls could be a real struggle.