The coalition with the CDU in 1966 broke on the subject of tax increases and it was followed by a grand coalition between the CDU and the SPD .
In the 1965 federal elections the FDP gained 9.5 percent .
The coalition with the CDU in 1966 broke on the subject of tax increases and FDP was followed by a grand coalition between the CDU and the SPD .
In the 1965 federal elections the FDP gained 9.5 percent .