Motorola will start selling its new Atrix Android smartphone in the UK from tomorrow, with 420 Orange mobile phone stores initially stocking the Froyo 2.2 handset. Orange will offer the Motorola Atrix for free from £35-a-month with 600 minutes of calltime, 750MB of data and unlimited text messaging. The 3G handset will also come with an optional accessory set including a Bluetooth keyboard, mouse and remote control and a dock allowing the Atrix to be charged and to connect to an external screen via HDMI. As a loyalty bonus, the HD Media Dock will be free to existing customers upgrading, or £40 to new Orange subscribers. Once the initial promotion is over, the set will cost £49.99.

Motorola is actually punting two docks for the Atrix. The HD Media Dock is designed to “use the phone to drive the entertainment centre”, while a Linux-based Webtop OS on the 11in-screen Lapdock will allow the Atrix to function as a full laptop. Curiously, while the handset itself runs the usual Google Chrome Lite web browser, the Lapdock – a battery pack with screen but no native storage – runs the desktop version of Mozilla Firefox.

When using the 1.1kg Lapdock, the Atrix sits behind the 11in display, hidden from sight. To ensure you don’t miss a call when watching a video or TV programme, you get an onscreen alert. Pull the phone out the dock to answer the call and playback automatically freezes, ready to resume whenever you’re ready. A speaker on the rear edges of the dock allows you to make hands-free calls.

Using this dock, say Motorola’s UK spokespeople, there’s potentially no need to take a laptop with you on the road. Several of the company's staff have reportedly been using the Atrix plus £Lapdock combination for their mobile processing needs. To join them you will need to stump up £299 or up your montly contract to a mighty £60.

The Atrix HD media dock, meanwhile, is a pure connectivity and charging dock. It adds an output to an HDMI port so video and music can be streamed to an HDTV, websites browsed and social networking updates and emails checked online.

Orange will be the launch partner for the Motorola Atrix (which has been onsale in the US since March), but its ‘Everything Everywhere’ network partner T-Mobile will swiftly follow. T-Mobile will start selling the device next month.

The Atrix is being billed by Motorola as “the world’s most powerful smartphone”. It boasts up to 48GB of onboard storage when a microSD memory card is used. The dual-core nVidia Tegra 2 ARM Cortex A9 processor runs at 1GHz and, along with 1GB of RAM, supports a 4in 540x960-pixel capacitive touchscreen. However, at launch it will be a Froyo 2.2 Android device, rather than running the newer 2.3 Gingerbread.

Back in February, Motorola told us this would be the case, acknowledging it was keener to get the Atrix onsale than it was to ensure the marginal feature enhancements of Gingerbread were included. Motorola told us today that there are no definitive plans for when the 2.3 upgrade will happen, though it’s still on the cards.

The Atrix sports almost identical hardware to its US cousin, which has been onsale on the AT&T network for the past few weeks. One major difference, however, is that the European version offers 3G connectivity, while the US model has a 4G cellular radio.

The Motorola Atrix is the first fruit of the Motorola Mobility Group  - a spinoff from Motorola Inc that was formed in January. Further devices along similar lines are planned, say Motorola, but the company is not looking at adding docks to other, currently less powerful, products in its line-up such as the Motorola Droid or Defy.