Army bomb disposal experts and police are investigating a suspect device at a Tory MP's office in Horsham.
Sussex Police, fire and rescue are at the scene outside Jeremy Quinn's office, with photos showing a bomb disposal vehicle and a fire engine on the road.
It is believed a package was delivered to the Conservative Association in Gough House, Horsham yesterday.
Police reportedly arrived first at the scene this afternoon before the bomb squad and fire service arrived at around 5pm.
West Sussex Fire and Rescue Service confirmed that two crews have responded to the incident.
Sussex Police, fire and rescue at the scene outside Jeremy Quinn's office in Horsham