As we welcome construction's fifth minister in five years, it's time for one further change: moving the whole, ever-diminishing portfolio to the Treasury

Just four weeks ago, Alun Michael, the minister for construction, was asked in the House of Commons if he would make a statement on the contribution of the construction industry to the UK economy. He began his answer by saying that it was one of the most important sectors of the British economy, as it accounted for 8.3% of the UK's gross domestic product and employing 2.1 million people.

Within days Michael was out of a job. He had not even made it to his first anniversary. He fell victim to Tony Blair's post-local-election reshuffle. That made it a total of five ministers in the past five years with Michael, Nigel Griffiths and Brian Wilson sandwiched between the new incumbent, Margaret Hodge and Nick Raynsford, who was the first of this run.

It is particularly disappointing that Michael has been returned to the backbenches as there were clear signs he was getting to grips with the industry's major issues and engaging with the sector in a meaningful way - something I've experienced myself through both the Major Contractors Group and the Strategic Forum.

Not only is there no continuty in the industry's political oversight but, frustratingly, the importance attached to construction within the minister's portfolio of responsibilities appears to be ever-diminishing. For example, during the first six months of Michael's tenure only 8% of his public engagements were construction-related; this is not a criticism of the man himself but a reflection of what seems to be a near-impossible task of giving the necessary and appropriate time and attention to our industry.

The latest reshuffle has exacerbated the situation as reduced resources in the DTI mean Margaret Hodge has an even wider range of responsibilities than her predecessors. She is now overseeing enterprise, growth and business investment, small business services, the company law reform bill and Companies House, as well as strengthening regional economies.

Perhaps construction does not belong in the DTI at all? There could well be a better home for it in another government department that exerts influence across the whole economy. I'm talking here about the Treasury and I believe that if construction ministers are going to make a difference in Whitehall they need to have the sort of power and authority that goes with a ministerial portfolio in the Treasury. All the drivers lie in the Treasury because that is where the purse strings are tied. It is through its procurement policy that the public sector client has the potential to be a powerful advocate for positive change and, as construction's largest single client, it is uniquely well placed to influence our sector above all others.

During the first six months of Alun Michael’s tenure only 8% of his public engagements were construction related

This was the point made by Lord Hunt, minister for health and safety, at the Buying for Life conference on public sector construction procurement in March. He said he wanted the public sector to be made up of exemplary construction clients that influenced the design, construction, maintenance and use of a building, and helped to raise health and safety standards for all workers involved in such projects.

The best means of achieving this is by the government putting on its select lists only those suppliers who have improved health and safety, who look after their workforce, who train and upskill them, who are improving quality and who are giving better value. Despite Office of Government Commerce guidance along these lines we really need a Treasury minister to take the extra step and say that this is a requirement, not just an aspiration.

Sustainability, too, would benefit from a Treasury minister fighting construction's corner. There is little evidence of joined-up thinking between government departments in this area and there is no one champion for sustainability within the construction industry. Our industry is working to make the construction process greener but the driver for more sustainable buildings lies with the Treasury, as it requires greater up front costs, though not necessarily greater whole-life costs. It is a sophisticated argument that can best be advanced within the walls of the Treasury.

This is not about criticism of individual ministers but rather of where the minister is based and how best to enhance the effectiveness of the way they represent construction - which, as the outgoing minister made clear in his final contribution in the role in the House of Commons, is a key industry at the very heart of the UK economy.