Community Security Trust volunteers have said they refuse to be frightened out of protecting British synagogues following the attacks in Denmark.
Michael, 54, from Essex, has worked with CST protecting synagogues and Jewish events for over 11 years.
He said: "I've heard from people who all of a sudden say, 'hold on, I didn't realise we were putting our lives on the line'.
"But the threat has always been there and that is why we do it."
CST said there was no change to the high state of alert in the UK.
Michael added: "In my 11 years, this has been the most intense time ever but that is because we had a level of complacency, thinking nothing could ever happen."
The volunteer, who already works in the security sector, said he was not worried about a copycat attack because "it is much more difficult to get arms in this country and getting hold of ammunition is near impossible.
"But the fact is that nobody is going to cope with an armed situation if it happens; we just have to hope we can stop people entering a building like Dan Uzan [the murdered guard in Copenhagen] did."
Andrew, 37, from Hendon is on the board of a small shul with a growing community. A year ago, he said, they had no security measures at all. "It went from a luxury to a necessity and, as far as I'm concerned, recent events speak for themselves.
"The police do what they can and the government recognises the need for protection, but the reaction is slow and incomplete. There is a strong sense that if we don't do it, no one else will."
Peter, 54, said he had not been on duty since the attack, and expected to be under pressure from his wife to stay at home the next time he is called. "I didn't get into it to walk away. I want to be there for my community. I'll be standing out there more nervous, but I'll be standing."
CST communications director Mark Gardner said since the attack in Paris, the organisation had faced unprecedented demands for its work, including requests to help fund security equipment at communal buildings.
Mr Gardner said: "Our 2015 budget for these grants had been set at £500,000. Within three weeks of the Paris attacks, this had been entirely spent."
He added they were overwhelmed by the support from their volunteer network, and continued to get help from the police.
Since Paris, 150 volunteers have signed up and been trained to guard Jewish buildings, events and synagogues.
