Bergegren was a leading figure in the Social Democratic party, a figurehead of its anarcho-syndaclist element. Bergegren was active in the
Swedish labour movement, supporting striking industrial workers during the
1909 Swedish general strike. Bergegren supported
direct action and in a speech at the second SAP Congress in 1891, he argued that social democrats should be prepared for "any violence whatsoever" and that this involved teaching "workers how to manufacture and use dynamite and daggers." Bergegren was fined for publicly declaring: “If the officers use violence against us, we will use the same means against them”. His solidarity work also extended to sheltering refugees at his villa in Agneberg. Bergegren's radicalism attracted support among the party's Youth League who gathered around him. As the party leadership moved to the right, Bergegren was expelled, although his revolutionary activism received continued admiration from younger socialists. Bergegren later turned to support
Bolshevism.
Contraceptive and reproductive rights advocacy Bergegren has been described as a "pioneer propagandist" for contraception. After Bergegren gave a speech promoting birth control in 1910, the Swedish government criminalised advocating for birth control. Bergegren's support for reproductive rights and contraceptive access was affected by seeing urban poverty in Hagalund. He gave a lecture titled
Kärlek utan barn (Love without children) in Stockholm on 7 April 1910. The conservative newspaper
Nya Dagligt Allehanda was outraged by Bergegren's speech and in an article published on 16 April 1910 the paper described it as "nasty propaganda". Despite being outlawed, Bergegren continued to lecture in support of contraception and reproductive autonomy; more than 50,000 copies of his lectures were printed and sold across Sweden. Bergegren was prosecuted and jailed for his active support for contraception on multiple occasions. ==Personal life==