The Tories took the local seat that had been occupied by the Liberal Democrat Norman Baker since 1997.
The sign proposes a "Tory tax" of 10 per cent on any customer who voted Conservative as one of the "‘tough’ decisions I need to make to ‘balance the books’ under your preferred government".
The sign also says Ukip voters should "shop elsewhere".
Woodruff has owned his shop off the high street for seven years.
Pictures of the sign went viral on social media.