On a chilly stretch of towpath by the Lee river in east London last week, Sir Paul Beresford, Under-Secretary of State for the Environment, donned his anorak to join hard-core walking enthusiasts as they celebrated European funding for a pounds 1.5m project to establish a 1,200-mile chain of "green" walks around London.
Though not on the same scale as last September's award of pounds 42.5m of millennium money for 2,500 miles of cycle tracks across Britain, it was a further instance of official backing for environmental projects.
The trouble is that militant walkers and militant cyclists despise each other nearly as much as they hate their common enemy, the motor car. What happens when both want to use the same land for their paths?
As Sir Paul clasped a cardboard cup of hot soup, trying to keep his hands warm, one answer to that question was being worked out at a highly- charged public inquiry just a few miles away - by coincidence, in the council chamber at Wandsworth, where Sir Paul used to be council leader. There, in a week-long hearing, cyclists and pedestrians traded accusations of intimidation and loutish behaviour.
There will be other such clashes as walkers and wheelers press their rival claims to the choicest routes. The Ramblers' Association, for example, is worried about plans for a cycle path along the Thames from London to Oxford - part of the millennium network - that would include stretches of the towpath reserved for walkers.
There have already been confrontations between hikers and mountain bikers on bridleways, notably in Scotland. Road rage has filtered down to Britain's leafy footways.
In keeping, as they thought, with the green spirit of the times, Wandsworth council last year announced plans for a cycle route across Tooting Bec Common. The cause of contention is that a section of the proposed mile- long route would be along Chestnut Avenue, a historic tree-lined path at present legally confined to pedestrians - though cyclists often use it. The council seeks permission to widen a section of the path and designate one side for cyclists and the other for walkers.
This is too much for the Balham Society, the local amenity group leading the campaign against cyclists on the common. Jeremy Jessel, a Balham artist who is on the society's committee, was the main objector at last week's hearing.
Mr Jessel, although a bike owner himself, believes there is no way that pedestrians and cyclists can accommodate each other. In his deposition to the inspector, he wrote of "a dangerous cocktail of fast and ruthless cycle messengers, experienced hard-riding commuters ... wobbly old cyclists [and] mountain bikers." He said that in the 339 reported accidents between cyclists and pedestrians in Britain in 1994, three pedestrians were killed and 339 injured, against only 82 cyclists hurt.
"Many actually see themselves as honorary pedestrians," he wrote, "and will not acknowledge that their bikes are, in fact, vehicles. Just as cars have driven cyclists off the roads, so will cyclists drive pedestrians off the footpaths."
One local resident, though, drew a different picture in his evidence. He thought the prohibition of cycling on the common was "perverse and contradictory", adding: "I have never observed a cyclist abusing a pedestrian." On the other hand, he alleged that Mr Jessel had been conducting a campaign of "intimidation and abuse of cyclists". Mr Jessel denied it.
Richard Goalen, Wandsworth co-ordinator of the London Cycling Campaign, says shared paths exist in many parks and research shows they are safe. While 20 per cent of all journeys in Britain are by bike, the figure for London is only 2 per cent, because of too few cycleways.
The British Cycling Federation favours shared paths. "You always get some people who aren't sensible and that's where the troubles start," says Jim Hendry, its chief executive. "You did get clashes with pedestrians in the early days of mountain bikes but people have realised that if bike riders don't obey the rules they will lose the access."
The Ramblers' Association is less confident that good sense will prevail. Derek Purcell, secretary of its Inner London area, says: "We are concerned at the plans of Sustrans [the civil engineering charity promoting the national cycle network] for the Thames route. We fear that shared use will detract seriously from facilities that pedestrians have from time immemorial enjoyed along the towpath."
Jeremy Iles, co-ordinator for Sustrans of the Thames project, says it has consulted the Ramblers' Association about their plans, most recently last week, and that other routes will be found for bikes where the towpath is too narrow for sharing.
"We aim to work out an amicable solution to bear in mind the needs of a variety of different user groups," he says. "There are issues to be resolved but the best way to do it is to talk in a calm and civilised way."
A laudable aim. Maybe that spirit of environmental unity will eventually spread to the battlefield of Tooting. This row has legs.