Hopson is charged with communicating one of the most complex areas of public policy and overseeing the biggest public sector merger since the the Department for Work and Pensions was created in 2001.
But he is full of laughter during our brief rendezvous, bearing no airs or graces. His disposition contrasts starkly with the imposing atmosphere of 100 Parliament Street - where he has been busy restructuring the 130-strong team by adding a strategic comms and customer insight function to the existing set-up. He took up his post in January, in anticipation of last month's merger of Inland Revenue and HM Customs and Excise, and plans to add another tier of senior comms management underneath him.
With 100,000 employees, the new department accounts for one-fifth of the civil service. It needs to shed 16,000 jobs by 2008 following the Gershon Review's recommendations on Whitehall efficiency - not an internal comms task to be envied. But Hopson is clear about the size of the task and does not seem the type to be easily daunted.
He rose to prominence in the PR industry during his ten years as Granada Media Group's corporate affairs director, during which time he saw off two Competition Commission inquiries and helped steer the takeover of Forte Hotels.
When negotiating his job specification upon joining Granada, he secured a chair at the boardroom table at just 31.
And on returning to the public sector - he spent two years seconded to the Department for Education and Skills while at Granada - he now has a seat on the HM Customs and Revenue operations committee. He has an open invitation to attend the executive committee meetings, giving him a say in the day-to-day management of the department.
UK Sport director of policy and comms Tim Hollingsworth, a former colleague at Granada, lauds 'his passion and enthusiasm', adding: 'It didn't matter if it was a major crisis or we were on the front foot campaigning, Chris really seemed to be enjoying himself'.
His nous for negotiation and diplomacy are put to the test during our interview when HM Revenue and Customs security guards approach us. They fiercely demand to know why he is having his photograph taken near the building's tightly policed reception.
Hopson allays their fears, calmly assuring them he has permission.
Indeed, he says his biggest challenge is to continue to manage his work-life balance well: 'It is the most important thing in my life. I have two young children and my passion is my family.'
Hopson's arrival at HM Customs and Revenue continues something of a family tradition. In addition to founding the only department store in the market town of Newbury, his father was the town's tax commissioner, an honorary unpaid position, tasked with settling disputes between the Inland Revenue and local businesses.
He sounds as if he has finally returned to his public-spirited roots - Hopson was chief executive of the SDP in its dying days. 'I moved from Granada because just making money for shareholders was not enough. If we don't collect taxes, what will pay for our hospitals and schools?'
HM Customs and Revenue touches the life of everyone in the UK at least a few times a year, when they go through the green channel at the airport or when they pay tax, explains Hopson. And if people don't think the taxman is collecting for the right reasons, people will be less inclined to pay, and this is a real concern for the department.
'People must not think they are being robbed, but that they are contributing to a fair society. The effective rebranding of the tax collection agency is crucial.'
While taxes can be notoriously complex, he adds: 'My favourite saying is "keep it simple, stupid".'
1989: SDP, chief executive
1989: Consultant, Corporate Communications Strategy
1992: Special adviser to David Mellor
1993: Director of public affairs, Granada Media Group
1996: Corporate affairs director, Granada Media Group
2003: Freelance consultant, Department for Education and Skills
2005: Director of communications, HM Revenue and Customs