In the 1972 general election, the three parties formed a political alliance called the "Progressive Accord" (Dutch: Progressief Akkoord; PAK) and presented a common electoral program (Keerpunt '72; turning point '72).
1972年大選，三黨組成政治聯盟「進步協議」（ Progressief Akkoord, PAK），並推出共同候選名單「轉捩點 '72」（Keerpunt '72）。