Conservative party headquarters in Worthing were egged and daubed with graffiti in the early hours of Thursday morning.
A nearby cafe owner managed to clean the premises before Tory officers arrived on election morning.
Agent Anne Chapman said: “I don’t think people realise the office is there for them. We are here to help.
“They are only attacking their MP who is working for them.”
The attack came hours before the start of a busy election day, which has seen a ‘phenomenal’ turnout, according to candidates at the polling stations.
Results for Worthing West and East Worthing and Shoreham are set to be declared at around 6am.
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