The battle lines are being drawn again over a proposed housing development on croft land.

A case that has already gone all the way up to the Scottish Land Court, but it is far from over. Indeed this one has the feel of being a landmark for our unique system of land tenure.

It has already moved one leading crofting lawyer to call for the existing legislation governing the sector to be scrapped to let parliament start again.

Certainly the system's continuing complexity is underlined in this case.

In March 2011, after obtaining planning permission from the Highland Council to build 10 houses on part of the croft they owned at North Ballachulish, Donnie and Liz MacGillivray applied to decroft the land so that the development could proceed.

But in July 2013, the Crofting Commission, the regulatory body, declared their application "incompetent" on the grounds that they had not purchased all of their croft and, therefore, did not qualify to apply to decroft any part of it.

However in December the Scottish Land Court ruled against the commission's approach declaring it to be a legal mistake. The commission has now announced it will not appeal that ruling.

So it is back to the drawing board, or rather back to the application form to the commission for permission to decroft.

But crofters' representative body the Scottish Crofting Federation (SCF) is calling on the commissioners to throw out any such request.

Four years ago the proposal drew opposition locally and the SCF supported a fight against the loss of croft land for such speculative building. Although the 2010 Crofting Act gives the Crofting Commission more powers to prevent such developments, the North Ballachulish case was beyond the reach of these powers as the application was made before the new legislation came into force.

FCS Chair Fiona Mandeville said this week: "This is a complex legal case, but at its heart is a plan to decroft the land to cash in with a speculative building development of ten houses.

"This croft is among the best quality land in the township. It is still able to be used productively by genuine crofters and it is simply unacceptable that crofting should be debased in this way by speculators."

She recalled that in 2005 the commission's predecessor body the Crofters Commission was the subject of stinging criticism. This was after an Inverness-based absentee crofter, who had bought a three-acre croft in the Argyll village of Taynuilt 10 years earlier, was given permission by the commission to establish 10 house sites on the land which could fetch up to £80,000 each. Not for the first time, the old commission was accused of failing to protect crofting.

Fiona Mandeville said there were similarities: "Beyond the legal complexities of the North Ballachulish case lies the simple fact that on the outcome rests the integrity of this regulated tenure. If the decrofting takes place against the strong wishes of the people there it knocks the stuffing out of another township in the south west Highland mainland."

Fiona is right to be concerned. Since the first crofting act in 1886, the very foundation and justification for crofting legislation has been to protect the people living and working on the land of the Highlands and Islands from remorseless market forces. It hasn't all been to create a land bank for future housing developments.

For the individual crofter in need of cash for his or her family, that may be of little comfort. However the rest of society can legitimately question what the point of protecting crofting is in the 21st century, if in the most picturesque tourist areas the crofters are allowed to cash in their land chips for multiple house plots.

Remove or drastically reduce crofts in these areas, in the likes of Argyll and Lochaber, and they are lessened, as is crofting itself.

But this case throws up another cause for concern which has already been raised by the McGillivrays' lawyer Duncan MacPhee in Fort William.

He points out that his clients now face the prospect of having their renewed application to decroft by the very same commissioners who ruled against it. Fair minded and above reproach they may all be, but it is unsatisfactory that the law puts them and the McGillivrays in this position.

A high court judge can't sit in an appeal case against a trial verdict or ruling during which he or she has been on the bench. No properly constituted tribunal can allow the same people to hear a case and then a subsequent appeal.

Technically this may not be an appeal, but it may as well be. One thing is for sure, it will take time and next month it already will be four years since the McGillivrays first lodged their decrofting application.

We haven't heard the last of this one.