In reality he was in contact with a group called ‘Guardians of the North’ who had set up fake Facebook profiles.

The 48-year-old admitted six counts of attempting or causing a child under 16 to engage in sexual activity.

Martin Liddiard, prosecuting, said the Guardians of the North, based in the North East, set up the fake Facebook profiles of girls aged between 11 and 14 with photographs and information about the schools they attended before waiting and monitoring any friend requests, ensuring contact was first made by the offender.

He said the purpose of these profiles was to identify ‘online sexual groomers’.

Thomson made friend requests to six profiles, all purporting to be of girls aged between 13 and 14 years.

Mr Liddiard said: “They were fortunately fake names and false profiles of non-existent young girls.

“Grooming is a significant part of what the offence is in itself.”

Messages sent by Thomson to some of the ‘girls’ included ‘are you a virgin?’ and ‘how large are your breasts?’

He also expressed a desire to have sex with the girls, asked them about a ‘threesome’ and if they wanted to know how big his penis was.

He also asked if they could take part in a ‘video chat’ over his laptop and asked questions about their ‘private parts’.

Mr Liddiard said: “Slightly more sinister is asking for phone numbers and handing out his own phone number.”

The Guardians contacted police on January 21, 2017 and told them they were outside the defendant’s Worcester address at 6am.

They handed over a sample of their evidence, including a USB drive, to police. They found Thomson by consulting the electoral roll, Mr Liddiard said.  

When interviewed by police he said there was ‘nothing he wished to say’. He had been of previous good character.

Thomson pleaded not guilty on October 5 last year but was the case was listed for pre-trial review on February 27 this year when he changed his plea to guilty.

Judge Jim Tindal said: “It’s a case which goes beyond sexual chat because it relates to providing his telephone number. It wasn’t pure fantasy.”

Addressing the defendant directly he said: “At the time of this offence you were a sad, lonely, isolated man with very little confidence.

“The fact that these were actual vigilantes pretending to be young girls has an impact of course on the case. No child was put at risk but this behaviour demonstrates that you are a risk.

“If you were prepared to do it once the thinking is you might be prepared to do it again and next time they might be real children you’re chatting with.”

However, he said there was ‘strong personal mitigation’ and ‘a realistic prospect of rehabilitation’, describing Thomson as having led ‘a troubled life’.

He said an immediate prison sentence would only increase Thomson’s sense of being ‘ostracised’, arguing it was ‘far safer for the community’ to have him confront his offending with the assistance of courses.

Judge Tindal jailed Thomson for 18 months but suspended the sentence for two years. He must complete 25 rehabilitation activity days.

A sexual harm prevention order which restricts his contact with children and use of the internet was made for a period of 10 years. He must also sign the sex offender register, also for a period of 10 years, and pay a £250 contribution towards court costs.

The judge made a forfeiture and destruction order in relation to the devices seized from Thomson by police when they searched his home.