Mr Dempster is the first full-time general secretary to be appointed by the Association of Head Teachers in Scotland - a mark of the determination of primary heads to raise their profile.
The association feels it has been left on the sidelines while the Educational Institute of Scotland dominates decision-making, particularly following the teachers' agreement.
In time, the AHTS plans to appoint field officers to support its membership across Scotland - and as part of its expansionist agenda is also planning to recruit a potential 5,000 heads and depute heads across primary, nursery and special schools.
"If I can't learn about teaching from 1,500 headteachers then I don't know where I can learn it from," Mr Dempster says by way of acknowledging that the issue of his non-teaching background will inevitably be raised.
The former civil servant said: "I am a generalist - you can see that from my previous job history. There is a skill in being able to pick up key areas and understand them quickly and get on with them."
Originally from Aberdeen, Mr Dempster graduated in public policy and management from Robert Gordon University before joining the civil service, working initially in the Scottish Office and then the Scottish Executive in the areas of criminal justice and social work services and latterly in recycling and waste.
His time there included a secondment to the international oil and gas technology company Schlumberger where he gained private sector experience in smart cards and national identity cards.
Most recently, before taking up his appointment to the AHTS at the beginning of December, he was secretary to the Mobility and Access Group for Scotland, a non-departmental public body which advises ministers on disability issues in relation to transport policy.
As general secretary of the AHTS, he believes he can make the transition.
"It is not a particularly different culture, dealing with a lot of public servants and interacting with other public servants. When I was in the Scottish Executive proper I had to move very frequently and you don't get to put down an anchor.
"But this really is a role I can stay in for a number of years, developing expertise through the membership and representing a dedicated group of professionals who really see their job not just as a job but as a vocation - that really appeals to me."
He also looks forward to the new-found freedom of being able to criticise ministerial decisions - something denied to civil servants.
Immediate priorities include developing relationships between the AHTS, unions, local authorities and the Executive. He will be developing the AHTS website and also trying to increase the membership of 1,350. "The difference between the AHTS and the EIS is that this is for the management," Mr Dempster said. "The EIS represents classroom teachers in the main, but how can it effectively represent a headteacher if a classroom teacher has got a complaint and the classroom teacher is also a member?
"The AHTS allows the management side within a school to have a separate channel to get local representation if the need arises."
Greg Dempster can be contacted at: firstname.lastname@example.org.