A Twitter troll who bombarded the Labour and Co-operative politician Stella Creasy with abusive messages has abandoned an appeal against his conviction.

Peter Nunn, 34, from Bristol, was sentenced to 18 weeks in jail last year after he retweeted menacing posts threatening to rape the then Walthamstow MP and branding her a “witch” in 2013.

Creasy was targeted after she supported a high-profile campaign launched by feminist Caroline Criado-Perez to put Jane Austen on the £10 note.

Nunn, who has already served his sentence, had lodged an appeal which was due to be heard before the common serjeant at the Old Bailey, but he backed out at the last moment.

The court heard that his circumstances had change “quite considerably” since his release.

Nunn’s lawyer, David Patience, said he had decided not to go ahead because his mother had been sick and he had childcare commitments to his daughter as his partner had dumped him following the trial.

Stella Creasy was targeted after she supported a campaign to put Jane Austen on the £10 note. Photograph: Laura Lean/PA

He said: “Following a lengthy consultation this morning, Nunn has reconsidered his position and he has decided that he would like in fact to abandon both the appeal against conviction and appeal against sentence.

“Since being released from prison his circumstances have changed quite considerably. His mother was admitted to hospital in January suffering from septicaemia and is still in quite bad health and that is something that weighs heavily on his mind.

“He also has childcare commitments to his daughter. His partner broke up with him subsequent to the magistrates court.”

The judge said he would not order Nunn to pay costs but said he must continue to abide by a restraining order to stay away from Creasy and Criado-Perez or face prison again.

He told Nunn: “I hope this has all been a salutary lesson to you. If you were to be in breach of the restraining order the overwhelming likelihood would be you would receive a custodial sentence.

“I express the hope that there will not be any recurrence of this type of conduct in the future. If there were to be, the court would be likely to take a much more serious view of it.”

Following a day-long trial at City of London magistrates court, Nunn was found guilty of sending a message that was grossly offensive or of an indecent, obscene or menacing character, by a public electronic network between 28 July and 5 August 2013.

The court heard that he began leaving offensive posts on 29 July, five days after the Bank of England revealed Austen would be the new face of the £10 note.

He retweeted a threatening message sent to Creasy which read: “You better watch your back, I’m going to rape your arse at 8pm and put the video all over.”

Over the next day, he sent a barrage of offensive messages to the MP using the Twitter account @protectys along with another account @eatcreasynow.

Another of his messages read: “Best way to rape a witch, try and drown her first then just when she’s gagging for air that’s when you enter.”

The self-styled blogger, who, the court heard, had ambitions of studying for a law degree, had claimed he sent the messages to exercise his right to freedom of speech and to “satirise” the issue of online trolling.

The part-time delivery driver, who declared himself a “feminist” during his own evidence, denied using Twitter to advocate violence or rape.

Criado-Perez was also the subject of Twitter abuse at the hands of Nunn, although the charge he faced did not relate to her.

District judge Elizabeth Roscoe imposed a restraining order banning him from any contact with either woman, who were not in court to see him sentenced.

In a victim impact statement, Creasy described how Nunn had caused misery to her and her family and led her to install a panic button in her home.