A special forces fantasist who held a pillow over his partner’s head while she cried “I can’t breathe” told jurors he did not want to murder her.

Instead, Edward Rudd claimed he had first placed a plastic bag over ex Cara Bryant’s head then held a pillow over her face as part of an elaborate prank. The 37-year-old denies attempted murder.

Put in the witness stand at Bristol Crown Court yesterday, the Melksham man said he had woken up in the early hours of December 11. He was in the back bedroom after an argument with his then girlfriend.

The preceding weeks had been tense. Following an attack on the house in November, the windows and doors had been kept locked and a plastic bag placed over the door. The couple had squabbled and Rudd had taken to playing “pranks” on Ms Bryant, including waking her in the early hours.

On December 11, he crept into her room naked then shone his phone’s torch on the woman’s face. He played a mash-up video he had made of an argument they had had the day before.

She didn’t scream and shout her objections but instead responded with what Rudd described as “snivelling”. “I felt a bit spurred on or encouraged,” he told jurors. He affected a high-pitched voice, based on Harry Potter nemesis Voldemort. The sound was captured on a video recording on Ms Bryant’s phone, although Rudd was unaware she was recording.

He claimed he’d gone downstairs to turn the electricity off. Prosecutors say Ms Bryant went to get some tobacco and told him to leave.

She returned upstairs first, then he came up with a plastic bag. He also let her dogs come upstairs, which they were not allowed to do except on every other Sunday.

He came back into her room and sat by the bed. “I then carried on, but this time I think making out I was possessed.” He claimed she had stolen a bottle of whisky from him.

Rudd began chanting nonsense words, based partly on Latin phrases. When she didn’t react he leapt on the bed and pushed the carrier bag over her head, a prank he had pulled once before on her. He heard her saying she couldn’t breathe but thought it to be an act.

He told jurors: “After a while I took the bag off from the top. I did feel some resistance, which I now believe to be Cara passing out or ripping it.” He denied stuffing the bag in her mouth, as she claimed.

Rudd added: “I had the bag over her head very loosely. It wasn’t tight or anything like that. It wasn’t tight around her neck.”

He held a pillow over her head. He said he had arched the pillow so it would not suffocate her. In the recording, an increasingly desperate Ms Bryant could be heard pleading with her boyfriend.

There came a point where Rudd said he felt he had gone too far, describing it as feeling like a hot-and-cold rush.

He repeated the phrase “I love you” and called Cara “babe”. He termed it “styling out”, defined as behaving confidently in order to manage an embarrassing situation.

“I had a little bit of a moment. What I wanted to do was say ‘sorry, are you okay?’ But [from] previous experience you apologise to Cara and you’ll never hear the end of it,” he said.

She called police, who were at the Melksham house the couple shared within minutes and arrested Rudd on suspicion of attempted murder. Interviewed by police he told a story about waking up to find the door open then answered no comment to detectives’ questions. “I believed if I had admitted to putting a bag over Cara’s head that I would be charged for what I had been arrested for. I knew I didn’t attempt to kill her. I just couldn’t see any other way out.”

Rudd came under fire from prosecutor Rob Welling, who accused the defendant of trying to kill his partner after she asked him to leave.

Mr Welling said: “This was an occasion where she was rejecting you. She’d had enough of you. That’s the truth. You can see that on the 10th she’d had her guts full of you. You were angry that another of your relationships were failing and you were going to make her pay, weren’t you?

“This was about you getting your own back on her.”

The prosecutor said Rudd knew his partner was ill. She had previously been in a coma and had other difficulties.

“She lasted longer than you imagined and you were worried about the neighbours, weren’t you? You then played a charade, didn’t you, do try and make out it was either you under some kind of influence and you were trying to charm your way out of it by calling her baby,” Mr Welling said.

“Cara knew you very well by December 11 she told the police ‘he’s trying to kill me’ and she was right.”

Rudd denied the barrister’s allegations.

The prosecutor asked why Rudd told a police nurse when he was arrested that he had been in the Royal Marines and served with the Special Boat Service – despite not having served with the elite special forces unit or been a Commando.

Answering his own question, Mr Welling told the defendant: “It’s because you want people to think you’re something other than what you are.” Rudd replied: “Perhaps.”

Rudd, of no fixed address, denies attempted murder. The trial continues.