Military trainers who have turned 10,000 Ukrainian civilians into soldiers in just weeks will put another 20,000 through their paces in the UK this year.

Recruits taking part in Operation Interflex undergo an intense five-week programme learning the international laws of armed conflict, trench warfare, urban fighting, weapons handling and firing, medical training and dealing with explosives.

The courses, which are being held at sites across the UK, will harness the Ukrainians’ “offensive spirit” and give them the skills to fight effectively and survive despite coming in with little or no experience, a senior officer said.

The course is similar to what British Army reserves undertake, but it has been tweaked to reflect the reality of the war in Ukraine and has direct input from Armed Forces of Ukraine (AFU) soldiers who have fought there.

The Ministry of Defence invited the media to observe training at an undisclosed site in the north of England, as the anniversary of the start of the war approached.

Platoon after platoon of recruits battled their way through a trench warfare exercise where a series of trenches were dug into the northern moorland and defended by international troops.

Smoke grenades and loud bangs heightened the reality of the exercise, which culminated in a planned attack on a wood, as hundreds of blank rounds were fired.

It was a reminder that these recruits will be facing real bullets when they return to Ukraine.

Artem, 42, formerly working in logistics in Odesa, was impressed and thankful for the international trainers’ efforts.

He said: “They really care for us very much. They have a very high level of military expertise.

“Before the full-scale invasion I didn’t have any military experience.

“Me and my brothers in arms are more than sure this will help us to fulfil the combat tasks and it will give us more strength and resilience on the battlefield.”

Corporal Shaun Carter of the Princess of Wales Royal Regiment, normally based in Woolwich, said of the exercises: “We try to make it as realistic as possible, as close to what they will be up against in Ukraine.

“We call it ‘train hard, fight easy’. We have trained 10,000 last year, we want to do another 20,000 this year.

“They are extremely motivated.

“When they turn up they are civilians and in a short number of weeks they have gone from civilian to soldier.

“We get to know them, we learn from them, so it’s a two-way street. There’s a lot of admiration from us.”

The corporal was pleased with the way the recruits had picked up combat skills in the short course, saying: “They have come on leaps and bounds.”

Other recruits were undergoing training on urban warfare and learning from Swedish soldiers how to clear buildings.

Instructor Rasmus, a Swedish army captain who preferred not to give his surname, said the Ukrainians were highly motivated.

“It is hard work being a soldier,” he said.

“They are tired but keep going with a good spirit.

“We know this is for real and they will use this training in real situations and we are giving them the best training we can.

“They are progressing so well so they are fit to fight back in Ukraine.”