Complex sentence: Opposition to the constitutional changes was led by the New Democratic Party (NDP), which held the position that the proposed constitution would neither reduce the power of the Prime Minister nor strengthen the country's democracy.
Split into simpler sentences: Opposition to the constitutional changes was led by the New Democratic Party (NDP). The NDP advocated for a "No" vote on the proposals, holding the position that the proposed constitution would neither reduce the power of the Prime Minister nor strengthen the country's democracy.