In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.

But when the government has a strong prime minister the foreign minister may be may not determine policy himself .
In a classic parliamentary system , a foreign minister can potentially exert significant influence in forming foreign policy but when the government is dominated by a strong prime minister the foreign minister may be limited to playing a more marginal or subsidiary role in determining policy .