Summing up for the government in the second censure debate brought by the Socialist opposition in a week, Mr Juppe said that the reforms would go ahead, "gradually and with consensus", and would not be withdrawn.
Mr Juppe was speaking at the end of a day when more than one million people had taken to the streets of France in a huge protest called by two of the major public sector unions, the Force Ouvriere and the CGT. The demonstration, the seventh in two months, was by far the biggest so far and brought together employees from every part of France's diverse public sector: from railwaymen and staff of public utilities to hospital workers and teachers.
In Marseille, more than100,000 turned out around the old port; in the naval port of Toulon, the arsenal was blockaded for several hours; all road entrances to the cathedral city of Chartres were manned by pickets; and the channel ports of Le Havre and Dieppe were blockaded.
In Paris, where an estimated 110,000 people marched, tens of thousands of demonstrators were still waiting to leave the starting point, at Place de la Republique, when the leaders had already arrived at Nation, three kilometres away.
In scenes replete with revolutionary images, the dense column of marchers, often shrouded in smoke from hundreds of bright pink flares, wheeled slowly around the Bastille monument. Waving brightly coloured banners and balloons, they chanted, blew horns, beat drums and periodically burst out in folk tunes with anti-Juppe lyrics, or snatches of the Internationale.
People living in flats overlooking nearby streets encouraged those waiting to set off with notices stuck in their windows announcing (with some hyperbole) the huge turnouts elsewhere: "Marseille: 200,000; Rouen and Toulouse: 80,000; Bordeaux (where Mr Juppe is mayor): 40,000. Paris - how many?"
The enormous protests, whose numbers appeared to be totally unanticipated by the police, came after a weekend in which Mr Juppe had made concession after concession to meet objections raised by individual sectors, but refused absolutely to dilute the core of his welfare reforms.
Presented by Mr Juppe in the National Assembly on 15 November, the reforms switch overall responsibility for the health and social security system to parliament (from a joint council on which trade unions are represented) and are intended to cut a deficit which is currently running at more than 60bn francs a years.
They are part of an overall effort by President Chirac and Mr Juppe to cut France's budget deficit to ensure that it qualifies to join the single European currency in 1999, but also to modernise France's public sector and make it conform to European legislation.
The size of yesterday's demonstrations was variously interpreted as a last glorious gesture by the unions before they agree to settle - a view ruled out absolutely by the leader of the CGT, Louis Viannet, or as a real threat not just to welfare reform but to Mr Juppe's survival as prime minister.
While some trade union officials say they believe Mr Juppe's concessions are significant, rank and file opinion in the public sector seems singularly unmoved - an aspect which the government is likely to find worrying in a protest where the running has been made more by ordinary union members than their leaders. France has been without any national rail service now for almost three weeks, and Paris has been without all forms of public transport for almost as long.
So far, Mr Juppe has tried to deal separately with the most militant sectors and the most emotive issues. He appointed a mediator to discuss a contentious restructuring plan for the railways, suspended a commission to consider special public sector pension arrangements, and agreed to meet union representatives personally.
On Monday he agreed to the "social summit" demanded by the unions - but says that it will discuss employment policy generally, as well as public service pay and conditions. But this immediately provoked howls of rage from employers' representatives, who warned it will extending the dispute into the private sector.