Dressed as Batman, Robin and Captain America, the three men used a ladder to climb up the Foreign Office building onto a narrow ledge about 12 metres up on the corner of Downing Street.
But the dynamic trio did not breach security.
However, they unfurled a banner saying: "Access denied. Don't let Labour stop you being a Superdad" as a crowd gathered below and police tried to talk them down.
The Fathers 4 Justice group is campaigning for better treatment by the courts for divorced fathers - specifically in visitation rights to their children.