Dennis is a high profile figure in the financial industry. His role as Chief Economist for HSBC involves advising lending bankers on economic trends at a national level, as well as on industries and regions.

Before joining Midland Bank in 1978, Dennis worked for four years in Whitehall, for the National Economic Development Office. This was during the Labour government's Industrial Strategy Initiative, which was an attempt to improve the performance of the UK's manufacturing sector.

His first job on leaving university (Swansea and University College, London) was as an economist for a national trade union. Here Dennis was responsible for the preparation of pay claims, arbitration cases and the union's submission to various statutory bodies set up under Edward Heath's Industrial Relations Act.

His principal interests outside office hours are music and football and his publications include the definitive history of Fulham Football Club; the need for an Industrial Investment Bank in the UK; analyses of the textile and construction industries; and critiques on the recordings of Van Morrison, Joe Cocker and Ray Charles