A security guard caught in an MI5 sting after selling secrets to Russia has claimed he is "disgusted" with himself and hadn't thought about what he was doing.
David Smith, 58, hoarded documents and was caught filming a man he thought was a Russian "traitor" where he worked at the British embassy in Berlin.
But it was actually an undercover sting and the man was a British spook.
He was also approached by an MI5 "agent provocateur" named Irina posing as a GRU Russian intelligence officer.
Smith has admitted eight counts of breaching the Official Secrets Act after sending confidential documents to a Russian military attache.
He said: "I'm disgusted with myself, at the time I didn't think about what I was doing but now I've had one and a half years, I'm disgusted with myself and ashamed of what I've done."
However, he has denied he was a spy, claiming: "I was an obstinate brat."
Today he told a hearing at the Old Bailey that he was in a downward spiral of depression and alcohol after his wife, Svetlana, moved back to her home in Ukraine and Covid lockdown restrictions left him isolated.
He said he wanted to give his employers "a bit of a slap" because he felt undervalued and ignored.
He said: "I accept what I did. I was depressed, being alone all the time, my wife had gone back to Ukraine.
"I was angry at diplomats, there was a 'them and us' attitude at the embassy. There was bullying at certain points. I felt undervalued and angry."
Matthew Ryder KC, defending, asked: "Did you intend to cause serious harm?"
Smith replied: "At no time I just wanted to give the Embassy a bit of a slap because I didn't think it was treating me well."
Father-of-one Smith - who served with the RAF for more than 12 years before working at Gatwick Airport - lived in Crawley, West Sussex, before moving to German with his second wife, Svetlana, in 2013.
He began working at the British embassy in 2016 but said he quickly became angry at the culture of "bullying" and the "us and them attitude" of diplomats.
Smith told a Newton Hearing at the Old Bailey he previously supported the Ukrainian separatists in the disputed Donbas region of Ukraine.
But after visiting his wife there he saw "row upon row upon row" of freshly dug graves waiting for fallen soldiers from the frontline.
He said: "I thought, 'No-one should die for politics'."
After his wife moved home to Ukraine in 2018 and Covid restrictions were imposed in Berlin, he said he suffered problems with his mental health.
In a downward spiral, he began drinking heavily and suffered depression but when he approached his bosses for help, he said he was simply given a phone number for a helpline.
Smith was so angry he started collecting documents to show lapses in security and to "embarrass" his colleagues.
He said: "It was self satisfaction, like an obstinate brat. I had not planned to do anything like that, it was just something that happened."
He denied claims he was anti-UK and supported Russia, but admitted he had surfed "conspiracy" websites by David Icke and InfoWars "to get an alternative view on life".
Mr Ryder asked: "Did you intend to put anybody in danger?'
Smith replied: "No not intentionally, no. I've seen the statements from people, I've seen these harm statements. I can only apologise for any stress I have caused anyone. I didn't intend to do it.
"I just had a bit of an aggrievance and I just wanted to embarrass the Embassy in what way I can."
Mr Ryder asked: "Would you describe yourself as anti-UK or anti-Germany?"
Smith replied: "Not at all, no."
Asked if he was pro-Putin, Smith said: "Not in particular. My thoughts of Mr Putin are neither here nor there."
The Old Bailey yesterday heard that when Smith was arrested officials found he had a list addresses for British embassy staff stored in his locker - as well as a dictionary of Russian obscenities.
They also found a cartoon of President Vladimir Putin in a military uniform holding the head of Angela Merkel and the words, "Russia, please free us once again".
At his home they found a Russian Federation flag, as well as Russian books written in Russian Cyrillic, a Soviet Military hat and a Communist toy Lada car.
They also discovered a life-size cuddly Russian toy Rottweiler wearing a Russian military hat and books about female snipers who fought in battles between the Nazis and Soviet forces.
When he was arrested on August 10 he refused to take part in a police interview.
Smith, who is originally from Paisley, Scotland, was extradited on April 6 last year and arrested on arrival at Heathrow Airport for offences under the Official Secrets Act.
In November last year, Smith pleaded guilty to eight charges under the Official Secrets Act by committing an act prejudicial to the safety or interests of the state.
The prosecution allege Smith held strong anti-UK views and was in favour of Russia and Putin.
An examination of his finances suggest he was receiving unaccounted for funds, including 800 euro in cash uncovered at his home in Potsdam.
At the Old Bailey hearing, Smith has denied leaking secrets to Russia for money and claimed he only intended to "inconvenience and embarrass" the embassy, where he had worked since 2016.
But the prosecution say his deliberate engagement with Russian authorities by providing them with confidential and sensitive information demonstrates an intent to harm UK interests.
Smith is due to be sentenced at the Old Bailey on Friday.
