Kevin McNamara has resigned as the Liberal Democrat candidate for Thurrock after the party opened disciplinary investigations into tweets he posted in the past.
Mr McNamara said: "I am deeply sorry for the comments that I made that are currently being reported in the press. These words are deeply offensive and I apologise profusely to everybody that I have offended with these tweets.
"I would never want to undermine the voices of those communities with slurs or degradation and it's important that people who want to represent the public are held to the very highest standard. I am resigning as a candidate with immediate effect for the upcoming election.
"I apologise to all of those I have let down with my past conduct and will work hard to regain their trust."