In the 1963 elections the party performed particularly well. It doubled its seats to four. This success can be attributed to several developments: the rising opposition to the Cold War, the party's appeal to the developing students' movement and especially the anarchist Provo movement, for whom the PSP was the only acceptable party, and finally the CPN's internal conflicts – in 1958 three MPs had left the CPN and formed their own parliamentary party, led by Henk Gortzak, called the "Bridge Group" (Dutch: Brug-groep) and unsuccessfully competed in the 1959 elections. The group subsequently founded the Socialist Workers' Party (Dutch: Socialist Werkerspartij; SWP). This internal dissent had caused the CPN to fall to only one seat in the 1963 elections.