A Republican candidate who called a Florida high school shooting survivor a "skinhead lesbian" and called another a "bald-faced liar" has quit the race for Maine's House of Representatives.

Leslie Gibson was widely criticised for insulting the survivors of February's shooting, which killed 17 people.

Leslie Gibson has since deleted his Twitter account. ( Twitter: @LeslieEGibson2 )

The Portland Press Herald reported Mr Gibson said he was walking away from the race with his "head held high".

One of the teenage students he attacked online was Emma Gonzalez, a leader in student efforts to combat gun violence.

Mr Gibson tweeted that there was "nothing about this skinhead lesbian" that impressed him.

Ms Gonzalez, a Year 10 student at Marjory Stoneman Douglas High School, delivered an impassioned speech in front of thousands last month, calling out US President Donald Trump over his ties to the powerful National Rifle Association.

Sorry, this video has expired Emotions run high as students demand gun law reform after 17 killed in Florida

Mr Gibson made a quasi apology to Ms Gonzales, telling the Sun Journal it was "not appropriate to single out the Parkland students", but that he still stands firm in his defence of "our constitutional rights".

He said he served in the military and took an oath "to uphold and defend the Constitution of the United States".

Mr Gibson had been unopposed in the 57th District contest. Now Republican Thomas Martin Jr and Democrat Eryn Gilchrist are running.

Ms Gilchrist said she was "horrified" at the idea of Mr Gibson representing her.

Mr Gibson has since deleted his Twitter account.

AP