"Stop Extremism!" urges a red billboard in a quiet village outside Zurich above an image of a scowling woman wearing a black headscarf and face veil.<br /><br />The billboard is part of a campaign by the far-right Swiss People's Party (SVP) to ban face coverings in public and which will be voted on in a binding national referendum on Sunday. Opinion polls suggest most Swiss will back it and the ban will become law.<br /><br />"In Switzerland our tradition is that you show your face. That is a sign of our basic freedoms," said Walter Wobmann, an SVP member of parliament and chairman of the referendum committee.
