The FFT announced two years ago that it was committed to redeveloping the current site of the French Open, which was built in 1928, rather than moving out of the centre of Paris to a new venue.
Under pressure to match the facilities at the other grand slams and well aware countries in the Middle East and Asia would jump at the chance to host one of tennis' four big tournaments, the FFT knew it could not stand still.
But the project was controversial because it involved expanding the cramped site into the neighbouring botanic gardens, with their historic glasshouses.
The plans had the backing of the city authorities but they were thrown into doubt in March when an administrative tribunal found in favour of three local associations, who claimed the redevelopment would harm the environment.
The FFT and the authorities immediately appealed but they are unlikely to hear whether they have been successful before the end of the year.
However, far from the project being on hold, a new agreement has been signed between the FFT and the city and the building permits will be filed in two months' time.
The plans have been tweaked to try to earn the backing of the local associations and next month they will come together at a committee meeting.
Gilbert Ysern, French Open tournament director and director general of the FFT, said: "We are, together with the city of Paris, really convinced that our project is a good one.
"Of course, it's good as far as we are concerned because it serves our interest and it really addresses our concerns and all our needs will be met with these new facilities.
"But we also know that this project is conducted in whole respect of whatever needs be respected, be it French law, be it the environment, be it the architecture.
"We are in a gorgeous place that is part of Paris and it bears a lot of history. All of this is 100 per cent respected in our project, so we don't see why and how in the end we could not be allowed to develop that."
The main changes will see the primary show court, Philippe Chatrier, largely knocked down and rebuilt, with the addition of a roof that will mean night sessions in Paris for the first time.
The bullring-shaped Court 1 will be knocked down and a new court built in the botanic gardens, although none of the historic glasshouses will be affected and the court itself will be surrounded by new glasshouses.
The expansion will add an extra 3,900 square metres to the site, with an emphasis on green spaces, and, although the number of courts will actually reduce by one, a new training centre will provide practice space for players.
The cost has increased to 340million euros, although the proportion of public funding remains at 20million euros.
Current plans are for work to begin in 2015, with the garden court completed in 2017 and Chatrier, which will be redeveloped around the French Open, a year later.