Being an accountant is a far cry from your first role in central government. What happened?
I started out working on the policy side. I was head of the home, legal and communities team at HM Treasury between 2003 and 2007, and I also spent some time in the prime minister’s strategy unit.

Then I moved to the UK Border Agency, where I was director of finance for two years. While I was there the civil service started encouraging finance staff to train professionally and it seemed like a great opportunity.

You were offered a choice of professional finance qualifications so why CIMA, and how has it helped you in your career so far?
It was the qualification that seemed to have the most recognition in both the public and the private sector, and it can potentially open up all sorts of doors.

Although I’d been doing a full-time job in finance for quite some time my training taught me a lot about accounting that I didn’t already know and quite a lot about how to pass exams, which was a new experience.

Really understanding accounts has changed the way I relate to financial information and the judgments I make about risks, frameworks and processes.

CIMA training forces you to think in a way you would not do otherwise. It enables you to engage with the entire accounting process properly and to really understand what the numbers are telling you

It’s made me a better finance manager - and a better policy manager.

The Treasury currently has ministers who are trained accountants too. What impact does this have on the department?
The exchequer secretary to the Treasury, David Gauke, and economic secretary to the Treasury, Justine Greening, are both accountants and it does have advantages. .Justine Greening has a particular role to champion the Government finance community.

Because of her training and experience she understands and cares about how financial processes and systems work, so is better able to support, encourage and champion the changes we are trying to make in the department.

The financial world and the Treasury have changed since you previously worked there. What challenges has this created?
There is a lot less money this time around and the public sector is shrinking rather than growing.

The country has been through an extraordinary financial sector crisis and the Treasury has had some enormous challenges to grapple with.

A few months ago, for example, there were around 1,400 people in the finance and commercial department, yet by 2014 there should be 1,000, so I have to make sure that they are the right people and get them working in a different way.

The focus on getting proper value for money means a change of culture. I also have to reduce departmental overheads, such as the cost of the building and IT, but we know what we are going to do.

At the moment the Treasury is on four floors of one building, but it is going to be concentrated on to two floors; we can cut costs by renting out two floors and making better use of the remaining space.

Having the plan is the important thing because we need the right structures and processes in place to ensure people can focus more on doing the things we employ them to do.

I have to ensure that people are still able to do their jobs, just like the director of any other government department. Although we are developing and reshaping the finance and commercial functions at the Treasury, we still have to provide the support structures required by the people who are setting policy.

Ministers have to work though some huge issues and it’s my job to free them up so that they can focus on doing this.

The department also has to manage the public money that’s been pumped into the banking sector. This must be a very different undertaking? I sit on the board of UK Financial Investments (UKFI), which was established by the previous government to hold the public’s stakes in lenders, including RBS and Lloyds Banking Group, and this gives the Treasury an operational focus that wasn’t there before.

In the past the department has been involved in privatisations, but we have a more direct responsibility for the public investment in these organisations and this operational side is new.

The Treasury’s objective over the next four years is to find the right way to exit from this, when the time is right. We have to get that public money out and return the banks to the private sector while adding value to the taxpayer, and then we can get back to being a Treasury that runs as a finance and economics ministry.

Meanwhile, my CIMA training is proving invaluable. When investment bankers talk about how to value companies, for example, I already know the strengths and weaknesses of any given model.

I understand things such as tangible asset values and equity breaks because I did them in my training. Understanding what’s possible and the mechanics of how these things are done, added to my policy background, gives me my own financial frame of reference so I can exercise judgment.

I can recognise if what they are saying is based on assumptions, which often happens. Being a trained accountant means that I am equipped to check and challenge the information with and to make my own informed and independent judgment about whether I agree – or disagree.

Managing other aspects of the fallout from the global economic crisis must also be challenging…
Because it’s had an impact on all sorts of things it’s changed the function of the department, giving us a different and more difficult role, and not just because of the involvement with UKFI.

The Treasury is also responsible for policy on regulation in the financial sector, where the Government is planning a major reform of the system, and with many of the financial sector interventions sitting on the Department’s balance sheet, my team and I are working on a lot of things that less-recent predecessors were not involved with.

Global instability in the financial services sector prompted a bigger recession and a bigger deficit so we are simultaneously trying to manage the money the country has invested in the banks, tighten public spending and adapt to changes in financial regulation, while overseeing enormous changes within the department.

All of this at a time when the global political situation is uncertain. The Treasury must understand all of the potential risks and threats, including some things that you could not possibly have anticipated, such as the Arab spring and the Tsunami in Japan.

It must be flexible enough to adapt to anything that comes along. My role is all about having the right people, doing the right things, in the right place, so that they can support the people who set policy, so that they can continue to do that well in this rapidly moving environment.

What advice do you have for aspiring CIMA students looking to follow your path?
The same advice as I give to my finance people in the department. You have to be able to tell a story with the numbers you present, because a lot of the time you will be talking to people who do not understand the technicalities of finance.

You need to take an interest in more than the money. Find out what the organisation is doing and what its organisational and strategic objectives are, so that you know which direction it is taking and how the finance story can help facilitate and shape this.

THE SUSTAINABILITY ISSUE: ONLY 7% OF PEOPLE TRUST COMPANIES' CLAIMS OF ACTION ON CLIMATE CHANGE (SOURCE: THE CARBON TRUST)