It will be the first taste of freedom in more than two years for Prisoner HG-1031, otherwise known as Lord Brocket.
Charles Ronald George Brocket is deemed to have paid his debt to society. Jailed for five years in February 1996 for a pounds 4.5m classic car insurance fraud, he has earned himself an early release through good behaviour. One of the first social engagements for the disgraced peer will be a celebratory lunch hosted by Nigel Hadden-Paton, an old friend from Household Cavalry days, and his wife, Bumble, at their Hertfordshire estate on Sunday.
The lunch, complete with champagne, barbecue and jazz band, has been described, rather endearingly, as a "breaking-out party". Lord Brocket's mother, who styles herself Mrs Colin Trotter, is expected to be among the assembled friends and family.
But friends say that Lord Brocket, chastened by the privations of prison, is a very different man from the cocky and egotistical aristocrat who thought he could stage the theft of four of his own classic cars, collect on the insurance and get away with it.
The future looks bleak indeed. His marriage, to the former Vogue model and society beauty Isa Lorenzo, broke down in the early 1990s. She now lives in Puerto Rico with their three children, none of whom he has seen since becoming a guest of Her Majesty.
The Third Baron does not even have his ancestral home to return to. Brocket Hall, the 50-bedroom Georgian pile that he inherited at the age of 16, has been leased to a German entrepreneur in order to pay off massive debts. It is now a hotel and conference centre.
It was the burden of those debts that prompted Lord Brocket to report three antique Ferraris and a Maserati stolen - but insurance companies were not easily fooled.
Eton-educated Brocket, once a lieutenant in the 14/20 Hussars, had a bad time in prison. Punched, kicked, slashed with a razor and repeatedly threatened, he was transferred from one jail to another - Wellingborough, Littlehey, Ford open prison and, most recently, Springhill. He has been depressed, and near-suicidal.
For Lord Brocket, the euphoria will be brief. He plans to ask the parole board for permission to fly to Puerto Rico to see his children. After that, he will have to decide what to do with the rest of his life.
Still, most newly-freed prisoners have a more difficult time of it. He will receive an annual income of pounds 170,000 as a result of the leasing agreement on his home. No doubt that will be a helpful stepping-stone on the road to rehabilitation.