Ayrault travelled to University Paris-Est in Val-de-Marne to reveal details of the historic Grand Paris or Greater Paris project for the French capital and surrounding Ile De France area.
The scheme will see billions of euros invested in transport links on a scale not seen since the region's RER train service was built in the 1960s.
The cornerstone of the project is the ‘Grand Paris Express’, dubbed the supermetro – a massive expansion and update of the rail and metro network in and around Paris.
The project was inherited from the former administration, after it was first launched by former President Nicolas Sarkozy in 2007. Back then some on the left criticised the scheme but the now the current government are now hailing it as "historic".
In an interview with French daily Le Parisien the French PM Ayrault said the current transport system in Paris was not up to scratch.
"The Ile de France represents 30 percent of the country's wealth. It's the richest region, the most powerful and where the most jobs are. But its also a region where there are a lot of daily difficulties, especially when it comes to travel," he said. "For a large number of residents travelling to work is a nightmare."
"The objective of the project is to put the Paris region at the top of the world's best cities in terms of finance, attractiveness and also solidarity".
The cost of Grand Paris is estimated at €27 billion, which is around €6 billion more than originally intended. As well as being over-budget the scheme is also behind schedule and will not now be completed until 2030, five years beyond the original estimated finish.
Asked whether France could afford to invest so much at a time of economic crisis Ayrault told Le Parisien: "Just becasue we are fighting against debt does not mean we are forbidden from investing in wealth and employment."
The so-called ‘super-metro’ is set to add 200 km of tracks and 72 new stations to the existing system. Among the main changes are the following:
After transport, the second major component of ‘Grand Paris’ is in the sphere of housing, with Prime Minister Ayrault due on Wednesday to confirm plans for the construction of 70,000 homes per year in the Ile-de-France area, an increase from the current annual rate of 40,000.
Wednesday’s anticipated announcement comes after an initial, long-running power struggle between the centre-right national government of former President Nicolas Sarkozy, and local Socialist party leaders, most notably Paris mayor Bertrand Delanoë and regional authority president Jean-Paul Huchon.