When Sarah Brown "Twittered" to the world that she would not eat veal at the G8 summit in Italy, it reignited a fierce debate about the differences between the way the UK and rest of Europe treat young male calves.

The Prime Minister's wife bravely risked the wrath of diplomats and government chefs with her breach of protocol.

"Am hoping that no veal served at lunch again today - have declined it twice this trip as just feel very strongly about it," remarked Mrs Brown on Twitter.

Her comments helped exposed the differences between the UK and Italy, where veal is reared in conditions this country would not tolerate.

Since they don't produce milk and have been traditionally considered unsuitable for beef production, British calves have tended to be killed at birth or sent on long journeys by lorry to the continent, where there is a huge market for veal and a disproportionate number of veal farms.

According to Compassion in World Farming (CWF), the biggest EU producers are France (1.6 million calves), the Netherlands (over 1.3 million) and Italy (over 870,000).

The UK market for veal has dropped dramatically since the issue of animal welfare came to light, so it has been worthwhile for British dairy farmers to find other markets. Almost 250,000 calves were transported from the UK to the continent between May 2006 and July 2008.

In order to keep the flesh of young male calves white, they are fed only milk and given little exercise. This can lead to digestive problems, anaemia and physical suffering because in order to stop muscles developing they are kept in pens to keep them still.

The use of the infamous veal crates for transportation has been banned in the EU since 2007, but CWF says there is still concern about welfare standards in the EU. Many veal farms keep the animals indoors, away from grass for grazing.

Recently, however, Britain - and Scotland - has been rediscovering a taste for the unusually tender meat, driven by a suspension on live calf exports due to fears of bovine TB. This ban has led to a surplus of young calves - and a new vogue for veal.

By feeding the young animals a mixture of mother's milk and grass, and with plenty of space to graze and play, their meat is pinker than traditional veal - and is called rosé veal.

Marks & Spencer were the first high street food retailer to launch high-welfare British rosé veal last year, produced exclusively by a family of dairy farmers in Scotland.

Chris and Denise Walton have gone one step further by raising beef veal on their organic Berwickshire farm. Peelham "ruby" veal from Scots breeds Luing and Aberdeen Angus is unique in Britain, and sought-after by top chefs such as Jamies Oliver, as well as delicatessens Kember & Jones and Peckhams in Glasgow.

Originally conceived as a business solution to the beef price crisis of 2005, the couple wanted to find a market for their young male calves, and have never looked back.

"We debated over whether to name it new season beef, but all our chefs told us they wanted it to be called veal, so we christened it ruby' to distinguish it from rose," explained Denise Walton.

Calves stay with their own mothers grazing naturally until natural weaning begins when they are about eight months old. "At this age there is more intra-muscular fat drawing flavour to the muscle than traditional dairy veal," said Walton. "This is also when they are at their prime of production."

They argue that killing the animals at this stage rather than the traditional 24 months is actually kinder, because they are naturally weaning.

Ross Minett, campaigns director for Scotland's leading animal protection organisation, Advocates for Animals, said: "A significant number of people in the UK choose to eat veal. Most of this veal will come from other European countries where welfare standards are in the main markedly lower than here in the UK," he said.

"We therefore recognise that rearing calves for higher welfare veal in the UK is more humane than the alternatives of disposing of them by shooting or live export."