A senior officer has said there will be “nerves” among military personnel who are missing Christmas leave to drive ambulances during NHS strikes on Wednesday.

About 600 members of the Army, Navy and RAF from across the country have been drafted in to help during the walkouts, some of whom have never driven the vehicles before.

Lieutenant Colonel James Shaw, Brigade Major of the Household Division, said the experience would be new to some personnel but troops were “confident” and had “a huge amount of initiative”.

The officer, who is overseeing training for the task at Wellington Barracks in London, said: “I think there’ll be a few nerves going out tomorrow – it’s a really important task and I think we’re incredibly proud.

“And obviously being military, you just want to do the best you can possibly do on this sort of thing, so I’m sure there will be a few nerves.”

Members of the armed forces taking part in the two days of training at the barracks said they were “nervous” but “honoured” to cover for ambulance workers, despite having to sacrifice time off.

Asked how he felt about being drafted in during the holiday, Lance Corporal Connor Roberts said: “I’m absolutely fine. I think it’s something that we’re used to, giving up our time to various things, so it’s an honour to come down and help the London Ambulance Service (LAS).”

He added: “I think it’s normal to be a little bit nervous but feeling quite honoured to come down and do my part.”

Sapper Terry Obeng said: “I’m all right, it’s better saving lives (than celebrating Christmas).”

However, the combat engineer said that responding to civilian incidents would “definitely make a difference” from the work with which he is familiar.

He said: “Definitely it’s going to make a difference, but that’s why we are here today, to train, so it won’t be that much of a surprise for us.”

He added: “An injured civilian is not an injured soldier. An injured soldier knows he is going to get injured. A civilian doesn’t know.”

Both men were among members of the armed forces who had not been behind the wheel of an ambulance until their training on Tuesday.

Instead they have a category C licence, meaning they are familiar with driving vehicles similar to ambulances and will have received extensive annual medical training.

Personnel covering for striking ambulance workers on Wednesday will not be allowed to break red lights or turn on blue lights when driving.

They are not due to be sent on critical emergency callouts or carry out clinical tasks but ambulance trainers have told them they should be prepared to hand equipment to their clinical partner if asked.