Conservative MP Sir David Amess has been stabbed as he met with constituents.,
Essex Police said they were called to reports of a stabbing in Leigh-on-Sea at 12:05 BST and arrested a man.
They said they also recovered a knife and they were not looking for anyone else in connection to the incident.
Former party leader Sir Iain Duncan Smith said he was “praying for a full recovery”.
He said on Twitter: “My thoughts are with David Amess MP and his family at this awful time.
“Praying for a full recovery following this appalling, shocking news. This angry, violent behaviour cannot be tolerated in politics or any other walk of life⦔