WITH Adolf Hitler poised to invade Britain in 1940, the nation was facing its darkest hour — so Winston Churchill realised it was time to fight dirty.

The Sun reports the Prime Minister’s answer was to create the Special Operations Executive, a unique squad of agents who would go behind enemy lines to carry out bombings, assassinations and acts of sabotage.

But he didn’t want a team of squaddies with standard, textbook skills and a military look that would stick out a mile.

Instead, he ordered the SOE should be drawn up from a broad section of society — ranging from different faiths and sexualities to disabled people and those from extreme poverty or wealth. Some weren’t even British.

But they all shared a desire to beat the Germans.

Dubbed “the Baker Street Irregulars” because of the address of their London HQ, the organisation is celebrated in a new five-part BBC2 series Secret Agent Selection: WWII.

Quentin Tarantino’s 2009 Oscar Winning Inglorious Basterds, starring Brad Pitt, tells an alternative history of two plots to assassinate high-ranking Nazi officials.

Secret Agent Selection: WWII sees 14 modern volunteers undergo the same training real SOE recruits went through.

We take a look back at a handful of the original recruits and their extraordinary feats.

THE SHOP ASSISTANT

When 22-year-old Violette Szabo’s husband was killed in battle in 1942, she decided to devote her life to killing as many Nazis as possible.

Previously a shop assistant at a department store in Brixton, South London, she joined the SOE and became a wireless operator in occupied France.

In 1944, Violette showed extraordinary courage trying to help a member of the local resistance escape a troop of Germans. She fended off 40 Nazis with just 90 bullets in her rifle.

Eventually, overwhelmed and captured, Violette was taken to Ravensbruck concentration camp, north of Berlin. There she remained defiant.

Once, during the daily roll-call, she even stepped forward and, instead of giving her name, performed a rendition of the Lambeth Walk. She was executed at the camp in 1945 aged 23.

The DRAG ARTIST

THE last person a Nazi would suspect of being an undercover agent would be a female impersonator.

So when former circus stage-hand Denis Rake worked for the SOE in occupied Paris, he took on the guise of a Belgian drag artist performing in the clubs of Montmartre.

As a gay man, who was 40 when he joined the team as a wireless operator in 1941, he had felt compelled to prove his worth in a world where homosexual acts were still illegal.

Eventually, when he tried to sneak out of Paris for a mission, he was captured and had his foot crushed during torture but escaped across the Pyrenees to Spain.

After the war Rake, who was awarded the Military Cross, returned to England where he worked as a butler for movie star Douglas Fairbanks Jr. He died in 1976 at the age of 74.

THE LIMPING LADY

Virginia Hall was a wealthy American society girl hired by the SOE because of her gift for languages — and ended up being branded by the Nazis “the most dangerous of all Allied spies”.

Known by her family pet name of Dindy, from 1941 to 1942 she coordinated the activities of the French Underground in Vichy, in occupied France.

Her cover was that she was a reporter for the New York Post. The Gestapo nicknamed Virginia, who was 33 when the war broke out, The Limping Lady because she had a wooden leg.

Her left leg had been amputated after a hunting mishap in which she had accidentally shot herself.

She nicknamed the false leg “Cuthbert” and would namecheck it in messages to command in England.

Despite facing constant danger, Virginia survived the war, escaped to Spain and was awarded an MBE. She then went home to the United States and worked for the CIA for 20 years. She died in 1982 aged 76.

THE FEARLESS ARISTOCRAT

Krystyna Skarbek was a Polish countess who hated Germans after they invaded her homeland.

The longest-serving of all of Britain’s female wartime agents, she was known as “Churchill’s favourite spy”.

Writer Ian Fleming is even thought to have based some of his Bond girls on her, including Vesper Lynd in Casino Royale.

She joined the SOE in 1940 aged 32 and operated in many areas of conflict ranging from Poland to Egypt, but her finest moment came in 1944 when she single-handedly browbeat the Gestapo into not executing a French army officer and another SOE agent.

Krystyna warned them that the Allies would soon be liberating France and they would pay the ultimate price if they didn’t release them. She was so convincing they complied and asked her to protect them from the advancing troops.

She survived the war but was stabbed to death aged 44 by a shunned admirer in the Shelbourne Hotel in London in 1952.

THE MINER HERO

George Reginald Starr was a mining engineer who joined the Army before being enlisted by the SOE because of his fluent French.

He was sent behind enemy lines, using his engineering skills to destroy communication and transport lines.

His crowning glory was stopping a Panzer division who were en route with crucial back-up to German forces fending off the D-Day landings.

George gained a string of honours including the Military Cross and survived the war. He then helped rebuild the German coal-mining industry before retiring to France where he died in 1980 aged 76.

His brother, John Renshaw Starr, also joined the SOE. He too survived the war – but it was a very close call.

In 1943, John went to France to create a spy network but was captured and sent to a concentration camp near Berlin. He escaped by passing himself off as one of a group of Frenchmen being evacuated by the Red Cross. He returned to Britain where he set up a nightclub in Hanley, Staffs. He died in 1996, aged 88.

THE BRIDGE BUILDER

Noor Inayat Khan was a British Muslim of Indian descent who won the George Cross for going behind enemy lines as a wireless operator.

Shy, delicate and devoted to playing the harp, she was nonetheless determined to do her bit for the war effort and joined the SOE in 1943.

Crucially, she also wanted to improve race relations between Brits and Indians by proving her dedication to Queen and country.

Noor explained: “If one or two (Indians) could do something in the Allied service which was very brave, and which everybody admired, it would help to make a bridge between the English people and the Indians.”

As the SOE’s first female wireless operator, she was responsible for sending vital messages coordinating sabotage missions and the location of weapons for resistance fighters.

But she was seized in France in 1943 and, after enduring ten months shackled by her hands and feet, she was executed at Dachau death camp in 1944. She was 30.

THE FOREIGN ASSASSINS

Jozef Gabcik and professional Czech soldier Jan Kubis were trained by the SOE to carry out a mission to assassinate top Nazi Reinhard Heydrich.

Nicknamed The Butcher of Prague, Heydrich was one of Hitler’s closest allies and the architect of the Holocaust.

The two young men’s quest to kill him was effectively a suicide mission, no exit strategy was ever planned by their superiors — and the men knew it.

But Jozef, 28, a Slovakian blacksmith, and Jan, 26, willingly carried out their orders, attacking Heydrich as he drove through Prague in May 1942. He died from his wounds a few days later.

After a massive hunt, the two were cornered in catacombs under a church. After a gun battle Jozef shot himself before he could be captured, while Jan was injured and died shortly afterwards.

Knowing they were likely to die, they had changed their wills to remember the two teenage sweethearts they had met while training in Shropshire.

THE MOVIE BOMBMAKER

By the end of the war, Nazis on the Continent were terrified of rats — because they kept exploding.

Movie set designer and art director Lawrence P Williams, whose films included Brief Encounter and Tom Brown’s Schooldays, used his skills to create props — including the bombs disguised as rats — for the SOE.

Other ingenious inventions included piles of fake horse and camel droppings containing devices that would shred the tyres of enemy vehicles.

Then there were the radios camouflaged as petrol tins and cans of olive oil.

His team, based just behind the Sphinx in Egypt, also painstakingly faked enemy uniforms and civilian clothing, right down to the underwear, so no English-style details could betray an agent working overseas.

They even made fake Chinese lanterns and Balinese wood carvings packed with high explosives, which agents in the Far East would sell to Japanese troops. He died in 1996 aged 91.