A "monster" sergeant major has been jailed for two-and-a-half years for sexually assaulting a lesbian soldier following a drink-fuelled party, in an attack which left her considering suicide.

Former Warrant Officer Timothy Jones, 40, was found guilty last month of a charge of sexual assault by penetration following a trial at Bulford Military Court in Wiltshire.

The court heard that Jones, who left the Army in April after 23 years of service, had been drinking with the victim, her partner, and several other soldiers from 9 Theatre Logistic Regiment during a barbecue at Buckley Barracks in Hullavington, in May last year.

The revelry moved into the bedroom of the victim, who cannot be named for legal reasons, where she was seen to kiss her partner before the couple were left alone in the room with the defendant.

The defendant then sent a text message to a friend saying: "LOL I'm lying between two lesbians, what should I do?"

The victim later woke up in her bed to find Jones had undressed her from the waist down and was between her legs sexually assaulting her.

Sentencing Jones, Assistant Judge Advocate General Alan Large said: "At the time of the offence you were the squadron sergeant major with an important role in discipline and setting of standards and junior soldiers looked up to you and respected you and your rank.

"You were an important part of their lives and they were entitled to have you treat them with respect and to keep them safe."

He added: "The impact that excessive alcohol can have on people's lives and careers is well-known to this court, the British Army and society in general. The Army expects soldiers to drink alcohol appropriately and you failed to uphold those standards on the night of the offence."

He continued: "We do not think you had sex on your mind when you went back to the room but as the sexual temperature rose that night and as you consumed more alcohol, to put it bluntly, you decided to try your luck.

"You persuaded the two remaining male soldiers to leave but you remained and some form of sexual activity was on your mind."

Judge Large added that he and the panel of senior officers judging the case had reduced the sentence by six months because of the defendant's good service record.

Lieutenant Colonel David Phillips, prosecuting, read a statement written by the victim describing how she had been left suicidal by the incident.

She said in the statement: "Since the incident it has affected me badly, I have been suffering nightmares nearly every night, I have been attacking my partner during my sleep.

"When the incident initially happened I thought about killing myself because I couldn't cope - I was angry, upset, depressed, I couldn't deal with it."

She continued to say she had difficulty with coping with busy places including public functions and added: "I am less confident, I am on anti-depressants and I suffer from anxiety."

She said that she had problems simply entering the corridor of her barracks if she could hear others there and said that her trust in others and the military hierarchy had gone.

The court heard that Jones joined the Army in October 1990 and was married to a charity fundraiser and they had two children, a 14-year-old son and a four-year-old daughter.

Lt Col Phillips said that the offence was a breach of trust by Jones, who was of previous good character and had served in Northern Ireland, Rwanda and Yugoslavia.

He had also received the long service medal, good conduct medal as well as medals for service in Iraq and Afghanistan.

Jonathan Simpson, defending, said that Jones, who he described as an "old dinosaur", had begun to admit his guilt for what happened having denied the offence throughout the trial.

He said: "That level of admission and insight from my old dinosaur just goes to show the extent there is a degree of understanding and self-reflection and the beginning of remorse and change.

"He wants to confront the monster that he was that night so it doesn't happen again."

Mr Simpson said that the group had drunk a "whole spectrum of alcohol" during the evening.

Mr Simpson said that Jones' wife was standing by him but his family was having to deal with the defendant receiving insults with people calling him a "nonce" and their son facing problems at school because of his father's offence.

Jones was also ordered to sign the sex offenders register for life.