UKIP bosses have slammed Martyn Aiken for leaving their party and becoming an independent councillor.
Dave Pascoe, press officer for North East UKIP, said he has "badly let down" those residents that voted him in as a councillor.
Mr Pascoe said: "We are very disappointed at Martyn's decision.
"He has badly let down all of the people that have supported him in his quest to become a councillor in 2008, his subsequent mayoral candidacy and his venture into parliamentary politics as the UKIP candidate for Easington.
"On face value, it appears he has sacrificed the principles on which he was elected."
Coun Aiken was not available for comment when approached by the Mail.