As Dennis Canavan steps out through his front door and up to the entrance of the Sauchieburn estate, a prominent black-and-white �private� signs marks the gateway.

As Dennis Canavan steps out through his front door and up to the entrance of the Sauchieburn estate, a prominent black-and-white "private" signs marks the gateway. The irony - that the convenor of Ramblers Scotland should have these signs right outside his front door - is not lost on the man himself.

"People are not welcome into this part of the land," he says as we walk along the leafy road. "This is precisely the sort of issue Ramblers has been campaigning on for many years."

He explains how access was "generally fairly good" under the previous owners, the Maitlands, but how things changed after the estate was bought by Glasgow property developer William Roddie. "Almost as soon as he moved in, obstructions started appearing - high fencing, locked gates, notices," says Mr Canavan.

Needless to say, this did not go unchallenged. The former MP and MSP informed Stirling Council, whom he says now seem intent on taking action.

It's a lovely afternoon and Mr Canavan's son Adam, seven, just back from school and dressed in a Real Madrid top, has taken a break from playing footie in the back garden to join us. We are walking at a gentle pace - it's less than a week since Mr Canavan, 66, had keyhole surgery on an arthritic knee - which allows plenty of time to talk about his latest challenge: the calamitous budget cuts being imposed on Ramblers Scotland by the UK Ramblers Association's governing council.

A funding shortfall means London proposes cutting the Scottish budget from £381,000 to just £81,000. The Milnathort office would close and all seven staff are threatened with redundancy. The team would be reduced to two, working from home, and neither would be part of the UK senior management team. Mr Canavan describes the plans as "completely unacceptable".

Ramblers Scotland has between 7500 and 8000 members who pay £25-£30 annually, so they contribute £200,000 to the UK coffers. Cutting the budget to £81,000 is "preposterous", says Mr Canavan, because Scotland would be getting back far less than it puts in.

But he stresses this is not simply a question of accounting. "The beneficiaries of our campaigning work are not just Scots, but people from south of the border and all over the world who come to enjoy our natural environment," he says. "Ramblers Scotland has a great deal of devolved responsibility. This decision has been taken by people who don't fully appreciate the Scottish situation.

"The Land Reform Act is probably the most radical access legislation in the world. It wouldn't have been as good as it was without Ramblers Scotland," he says, paying tribute to Dave Morris, Ramblers Scotland's director, and his "excellent" team.

He believes Ramblers' financial crisis may be temporary. In the meantime, a Save Ramblers Scotland campaign has been launched, calling on both members and non-members to pledge what they can - £25 if possible - to help raise £200,000 to avert the office's closure.

But if no negotiated settlement can be reached, he sees the formation of an independent Scottish ramblers' organisation as a real possibility.

He adds that the conflict Ramblers is facing is one that other Scottish voluntary organisations may recognise. JK Rowling resigned as patron of MS Society Scotland in April after the resignation of Scottish staff she described as "immensely dedicated", in a conflict between MS Society London and Scotland.

For Mr Canavan, this is personal. He has campaigned for the right to roam all his life. In the Scottish parliament, he was instrumental in getting important amendments passed to the Land Reform Act, including 24-hour access and access to royal property.

After stepping down from parliament in 2007 to spend more time with Adam, he became first president, then chairman of Ramblers Scotland, the culmination of a love of the countryside that began in his childhood in Cowdenbeath.

As an adult, he started running - completing 15 marathons - and has often trained in the country.

He also finds that walking helps his depression, something he has lived with for years, but that worsened as a result of the most profound personal tragedy.

In 1989, his son Paul died of skin cancer aged 16; then in December 2006, his son Dennis died of a brain tumour aged 35; three months later, his eldest son Mark, who had motor neurone disease, passed away aged 41.

"The depression comes and goes and sometimes it's very, very severe," he says, as we meander downhill through trees. "I find that physical activity, including walking, is therapeutic, even if I'm on my own. I get out in the countryside and I try to think positively about good things rather than depressing things.

"The worst thing you can do with depression is sit alone at home brooding." He is patron of the Falkirk and District Association for Mental Health, which has a walking club.

He is also passionate about plans to use the 2014 Commonwealth Games in Glasgow to get more people walking for their health. "We want, not just a nation of spectators, but a nation of participants," he says.

However, the funding crisis puts those plans in jeopardy.

Some Scottish members have threatened to resign over the London-imposed cuts. But Mr Canavan says: don't. "I would strongly discourage that, I think they should stay and fight because I'm sure if we stick together we'll be able to find a solution to this problem," he says.

He still hopes a negotiated settlement can be reached. He is preparing a submission for the chairman of the governing board, Rodney Whittaker, asking for the redundancy threat to be lifted and proposing other ways of saving money, such as publishing the magazine online or, more radically, relocating the London HQ to a rural area where costs would be lower.

But the London board is dominated by members from the south of England; there is only one for Scotland. Only she, the Welsh member and one other opposed the budget cut. If there is no positive response from the board to negotiate over the cuts, he foresees pressure to go it alone.

"I haven't yet had the opportunity to consult the Scottish membership on the possibility of an independent ramblers' organisation in Scotland, and I would hope that we could solve this problem within the existing constitution of Ramblers," he says.

"My personal view is that unless we have a constructive response from London HQ, then we may have to give very serious consideration to a completely independent organisation in Scotland."