French-style militant tactics could be used in the UK if ministers do not react to a mass display of rural frustration, a farming leader has warned.

As many as 40,000 people from Wales are taking part in the Countryside Alliance "Liberty and Livelihood" march through central London.

They are joining some 300,000 to protest against a ban on hunting with dogs as well as a host of issues central to countryside life.

About 280,000 people marched in 1998

Farmers' Union of Wales (FUW) president Bob Parry warned farmers may barricade roads and ports if activists' plea is not taken on board.

Hundreds of coaches from the Welsh counties were set to be head for what may be the biggest protest in Britain for 150 years, which began at 1000 BST.

As many as a 250,000 people were expected to flood into central London on Sunday, clogging much of the capital. An extra 1,600 police officers were drafted in.

Those protestors travelling from Wales will march from Downing Street to Hyde Park on the "Liberty" route.

	:	March Route
Liberty and Livelihood March

The march was initially provoked by the government's plans to ban hunting with dogs.

But it now represents a broad range of problems rural residents say they face in the countryside in the wake of the foot-and-mouth crisis, including prices paid to farmers for produce like milk and school closures.

March facts

Estimated to last 1000 - 1600 BST Two routes codenamed 'Liberty' and 'Livelihood' Start points at Hyde Park Corner and Blackfriars Both finish Parliament Square Dispersal points Victoria St and Westminster Bridge Static bands and five video screens en route 64,800 registered as 'in spirit' non-marching supporters

The latest May Day anti-globalisation demonstration required 4,000 officers - mainly because protestors refused to tell police in advance about their plans.

Friends of the Earth has sought to broaden the campaign to safeguarding the rural economy and letting farmers compete with large supermarket chains.

And former Wales football international Vinnie Jones is also backing the march.

But Bob Parry's comments - which he labelled an "eleventh-hour warning" - raise the stakes in the debate.

"DEFRA Minister Margaret Beckett will end up drinking from the trough of the last chance saloon if she refuses to take notice of the frustrations expressed at today's march," he said.

"If she fails to heed the strength of frustration felt throughout the British countryside, so prominently revealed by today's march, I fear people will decide to become more militant in their actions.

"The march is not just about retaining hunting. It is very much about expressing our growing frustration at Westminster-based politicians' refusal to recognise the many and various rural issues that need to be addressed urgently."

Devolution request

The FUW refused to back a recent one-day strike, when some farmers withheld their produce, and a protest this week which sought to have supermarkets raise the price they paid for farmers' milk.

Mr Parry also lambasted Ms Beckett whom, he said, had not gone to the countryside in the parliamentary recess to listen to farmers.

The Welsh Assembly's new rural economy minister, Mike German, had, however, been "listening intently" to farmers throughout Wales' summer farming shows season.

"It is high time the Welsh Assembly was given greater control over farming policy in Wales rather than the piece-meal approach of Mrs Beckett's DEFRA," he added.

'Incredible turn-out'

League Against Cruel Sports chief executive David Batchelor told BBC News Online he was "shocked" at Mr Parry's comments.

"It would be an outrage against parliamentary democracy to use threats of law breaking to intimidate the Government into not legislating for a ban," he said.

David Berry, 69, of Roch, Pembrokeshire, said at the march: "The turnout is incredible.

"Nevertheless, I doubt whether the government will listen but still it is absolutely important that we speak out.

"My wife's family are farmers and we are very concerned about the problems facing the countryside."