Peter Lilley, MP for Hitchin and Harpenden, has announced that he will not seek re-election this time after serving for 34 years.
It follows yesterday's announcement that Sir Alan Haselhurst, the region's longest serving MP, was also calling it a day.
Mr Lilley announced his attention in a letter to his local Conservative Association he wrote:
"With some sadness I have decided not to seek re-election for Hitchin and Harpenden. It has been an immense privilege over the last 34 years to represent the people of Hitchin and Harpenden and, before the boundary changes, the people of St Albans.
During his Westminster career he served in the Thatcher Government as Secretary of State for Trade and Industry and was later Secretary of State for Social Security under John Major and Shadow Chancellor and DeputyLeader under William Hague.