Badminton Horse trials LIVE on BBCi and this website, Sat 7 May Badminton on BBCi

Law rides Shear L'Eau, his Athens winner, and Shear H20 - who has twice finished in Badminton's top three.

Among the other elite Britons in action are William Fox-Pitt and Pippa Funnell.

Fox-Pitt partners Tamarillo - who he rode to Badminton glory last year - and Ballincoola, while Funnell partners her 2003 Grand Slam hero Primmore's Pride.

Like Law and Fox-Pitt, Funnell had been set to ride two horses.

But she was forced to withdrew her dual Badminton champion Supreme Rock last week after the 17-year-old sustained a leg injury in the build-up to this year's Gloucestershire Park challenge.

To have ridden a horse of Rocky's calibre has been a huge honour Pippa Funnell

It has since been announced that the much-loved horse will now be retired and will say his farewell to the sport in a special tribute ceremony at Badminton on Sunday.

Funnell and Rocky clinched back-to-back Badminton crowns in 2002 and 2003 and consecutive individual European Championship gold medals at Luhmuhlen 1999 and Pau 2001.

The pair also helped Britain land team silver at the 2000 Olympics in Sydney and were part of the GB line-up that helped secure bronze at the World Equestrian Games in Jerez, Spain, in 2002.

Funnell said: "To have ridden a horse of Rocky's calibre has been a huge honour. He will be greatly missed and has well earned his rest."

Funnell scoops Grand Slam

In total, Badminton 2005 - which carries a �50,000 first prize - has attracted riders from 17 nations, including the first entry from Croatia.

Twenty-five of the field will be tackling the championship for the first time, while New Zealander Andrew Nicholson and Australia's Andrew Hoy will be among a host of formidable veteran internationals pushing for honours.

The competition is the second of three annual eventing Grand Slam contests.

The first Slam event - Kentucky - took place last week and Law partnered Coup de Coeur to a brilliant third place.

This year's Badminton also kicks off the new British Eventing Premier League.

The league, with a winner-takes-all riders' accumulator worth �5,000 also includes Chatsworth, Bramham, Gatcombe, Thirlestane Castle, Bowmore Blair Castle and culminates at Burghley in September.

Badminton has also broken with tradition for Saturday's awesome cross-country phase.

Previously the course has changed direction year-on-year but this time riders will follow much of 2004's track with 11 new fences added.