I doubt that most MEPs found the LD's slogan offensive. Why should they, the LDs believe in and support the EU?
As for the BP, not only did their stunt have chilling echoes of Nazi behaviour but their rhetoric is strangely similar to this:
We do not beg for votes. We demand conviction, devotion, passion! A vote is only a tool for us as well as for you. We will march into the marble halls of parliament, bringing with us the revolutionary will of the broad masses from which we came, called by fate and forming fate. We do not want to join this pile of manure. We are coming to shovel it out.
Do not believe that parliament is our goal. We have shown the enemy our nature from the podiums of our mass meetings and in the enormous demonstrations of our brown army. We will show it as well in the leaden atmosphere of parliament.
research.calvin.edu/german-propaganda-archive/angrif06.htm