No. In England and Wales, the courts have the final say and are not bound by the terms of a prenuptial (or postnuptial) agreement.
However, such agreements may be important evidence of what the parties intend to happen. They may be influential. This is particularly so in short , childless marriages.
Prenuptial agreements can also be useful in providing evidence of what property was brought into the marriage. This is called non-matrimonial property. It is less likely to be divided equally, since it was the product of the marriage partnership. Having evidence of what properties or savings were brought in (if these were substantial) may be helpful, again if it is a short marriage.