IanD wrote:I'm not sure exactly what which clause of which Scots Assembly act is relevant
The relevant bit of legislation is the Land Reform Act 2003, which is accompanied by the Scottish Outdoor Access Code.
However, in England and Wales the relevant legislation is CRoW 2000, and orienteering events do not benefit under access rights since Schedule 2 of CRoW explicitly states that these rights "do not entitle a person to be on any land if, in or on that land, he engages in any organised games [...] [or] engages in any activity which is organised or undertaken (whether by him or another) for any commercial purpose".
Unfortunately, I'm not sure the political will exists to introduce something similar to the Scottish system in England and Wales - we don't have the same tradition of open access that the Scots do, and I get the impression that the BMC and the Ramblers are both fairly content with the terms of CRoW. I think the better bet would be to focus any MP-letter-writing specifically on getting the Forestry Commission to reduce their charges.