The mourning will be led by President Jacques Chirac, who built much of his presidential campaign and the first year of his presidency around his claim to be the spiritual heir of De Gaulle. He will be accompanied by the head of the Gaullist RPR party and Prime Minister, Alain Juppe.
Most members of the Gaullist-led coalition government and a number of MPs are also likely to be in attendance, many of them breaking their holidays to show their Gaullist allegiance. Although Debre, a lawyer, had significant ideological differences with De Gaulle - notably over France's place in Europe and independence for Algeria - the differences were such as to mark Debre during his lifetime as "almost more Gaullist than De Gaulle".
The announcement of Debre's death at the weekend was followed by a succession of tributes that illustrated not only the esteem in which Debre was held, but also the continuing strength of the Gaullists' clan loyalty.
Tributes poured in, the first from Mr Juppe who is still struggling to establish his authority at the head of the RPR party, and described Debre as "a great statesman whose sole ambition was to serve France".
Characteristically, the mood - and political usefulness of Debre's memory in the current political context - was caught by President Chirac, who described him as "a reference and an example" who personified "rigour, high moral standards, a sense of what is meant by the State, and unfailing loyalty to the founder of the Fifth Republic"- that is, De Gaulle.
Some of the earliest tributes came from the younger and most politically astute members of the government: from Margie Sudre, the minister for the Francophone world - a native of Reunion, the island for which Debre was MP for many years - and Herve Gaymard, the junior health minister, who at 38 is the youngest member of the government. To hear from their lips the sort of reverential sentiments uttered by politicians 20 and 30 years their senior was to appreciate the awe in which De Gaulle is still held and the extent to which the authority and unity of today's Gaullists rests on his memory.
Today, in his oration, President Chirac is likely to capitalise on Debre's role as a founding father of the Fifth Republic, but he will doubtless also take the opportunity to claim legitimacy for his current policies from their "Gaullist" origins. Paradoxically, these are the very same policies on which Debre was personally least in agreement with De Gaulle: Europe and the nation state, independent Algeria and defence policy.
A month ago, the announcement of cuts in the French armed forces and final arrangements for the ending of conscription was accompanied by the presentation to Mr Chirac - by the defence minister - of an original De Gaulle document: a letter the young Lieutenant-Colonel Charles de Gaulle had written in 1935, arguing for France's armed forces to be fully professional. The letter, which had been bought by the Defence Ministry when it came up for auction a few months before, was used to prove the incontrovertibly Gaullist character of reforms that are unwelcome to a large section of the French military.
According to one French obituary writer, Michel Debre was anguished in his later years by the question of how it was possible to be a Gaullist without De Gaulle. "Perhaps," said the commentator, "Jacques Chirac supplies the answer."Reuse content