There is another thread like this up. The long and the short of it is that their political leaders tried initially, and when they learned that they really had no choice in the matter French president Mitterrand tried to incorporate Germany as wholly as possible in Europe's institutions, and even Margaret Thatcher eventually gave up
The long and the short of it is neither Britain or France have a decisive say in the issue, it is the positions of the Americans, the Russians and the Germans themselves that matter.