Petty-criminal-gone-straight Terry Leather (Jason Statham) owns a failing car-sales garage and feels harassed by two debt-collectors. His friend, the photographer Kevin Swain's (Stephen Campbell Moore) ex-girlfriend, a former model named Martine Love (Saffron Burrows) offers Terry a chance to earn enough money to never worry about debt again: a bank robbery in Baker Street, London. Leather gathers his petty-criminal friends, including Swain, a pornographic actor Dave Shilling (Daniel Mays), a Cypriot mechanic named Bambos (Alki David), and an elegant con-man "Major" Guy Singer (James Faulkner). While scouting out the bank, Leather and Love enter and inspect the vault while Shilling poses for photographs by Swain. The gangster Lew Vogel (David Suchet), who keeps records of his pay-offs to police at Lloyds bank, happens upon Shilling and Swain.
They lease a shop named Le Sac two lots away from the bank and dig a tunnel under The Chicken Inn fast-food restaurant to reach the underground bank vault. Terry employs Eddie Burton (Michael Jibson), one of his garage workers, as a "watchman" with a walkie-talkie to sit on a roof to keep look-out. Martine, once caught smuggling heroin into Britain and wanting to avoid jail, set them up for this job on behalf of MI5, which desires the contents of a certain safe deposit box, No. 118. This box contains sensual and compromising photos of a member of the British Royal Family (in the film, Princess Margaret). The photos and box belong to a black militant gangster who calls himself Michael X (Peter de Jersey); he uses the photos to avoid trouble with the Metropolitan Police, and MI5 is charged with keeping the photos out of circulation.
As Terry's crew digs, the radio chatter draws the attention of a local amateur radio operator, who overhears the conversation and realizes a robbery is in progress. He calls the police, who begin to search their ten-mile radius and listen for concrete details to pin the robbery down. Terry's crew breaks through and loot the vault, as Martine goes for the photo deposit-box. A suspicious Terry opens it with her and, upon seeing the pictures, realizes Martine's hidden agenda. Among the photos are many of high-ranking government officials, including a senior MP, in compromising positions in a local S&M brothel. The robbers take these with money and other valuables. Terry arranges for alternate transportation "to be safe", throwing off MI5 who had intended to intercept them. Guy and Bambas escape with their share and Terry confronts Martine over the photos, who explains the unfolding predicament. The robbery discovered, the police corrupt ones receiving payoffs and honest ones began an investigation while MI5 continues their search. Also joining the search for Terry's crew is Lew Vogel, an organized crime figure worried about the contents of his ledger, which lists payoffs he made to police, which was stolen in the robbery. He informs Michael X that the royal 'portraits' had gone missing and Michael X becomes suspicious of Gale Benson (Hattie Morahan), a British spy who loves his American colleague Black Power militant, Hakim Jamal (Colin Salmon), and has traveled with him and Jamal to Trinidad.
Remembering the encounter with Shilling outside of the bank before the robbery, Vogel has him tortured for information with a sandblaster. Shilling breaks and Vogel goes to Terry's garage and kidnaps Eddie, the lookout. Meanwhile, a senior minister in the government, Lord Drysdale, is shown photos of himself in the brothel run by Sonia Bern (Sharon Maughan) and agrees to help absolve the robbers and secure them safe passage. Meanwhile, MI5 issues a D-Notice forbidding press reports. Police simultaneously release recordings of the walkie-talkie conversations in the hope that someone will recognize the voices. These recordings are heard on the radio by Terry's family. Vogel's accomplice, corrupt Detective Gerald Pyke (Don Gallagher), shoots Dave and threatens to shoot Eddie unless Vogel gets his ledger back. Vogel agrees with Terry to meet him at Paddington Station in London. During this time, Guy and Bambas are murdered by persons unknown, and Michael X has Benson killed in Trinidad by an associates. Terry has Kev give the same instruction to Detective Sergeant Roy Given (Gerard Horan), the officer in charge of the investigation, citing knowledge of corrupt officers under Vogel's control. He convinces Vogel to go to Paddington Station at the same time, offering him the ledger in return for Eddie's safe return.
Terry heads to the rendezvous while Martine meets up with Tim Everett (Richard Lintern), her original contact in MI5, on a bridge overlooking the scene. Vogel and his corrupt police arrive with the mechanic, but recognize the MI5 agents and run. The deputy head of MI5 (with Lord Mountbatten) hands over the passports Terry bargained for, in return for the photos of the princess. Terry then chases Vogel and in a fight knocks out Vogel and his thugs, including corrupt Detective Nick Barton (Craig Fairbrass). Detective Given, officer in charge of the investigation, arrives to see the robbers arrested. He speaks with the MI5 officers present, who direct police to let the robbers go. Terry gives the ledger to the police officer before he, Kevin, and Eddie leave the scene. Vogel and the corrupt officers are arrested instead. Everett personally supervises Michael X's arrest in Trinidad and Tobago and has Benson's remains exhumed for reburial in Britain. The final scenes have Terry and Martine saying good-bye, and Terry and his family enjoying a relaxed and carefree life on a small motor yacht of their own, off a sunny beach.
The epilogue states that the revelations about the brothel forced many government officials to resign. Scotland Yard begins investigating the corrupt officers named in the ledger. Michael X was hanged in 1975 for Benson's murder and his personal files are kept hidden in the British National Archives until 2054. Vogel is imprisoned for eight years for crimes that were unrelated to the robbery. The murderers of Guy and Bambas have never been found. About 4 million worth of materials and money were stolen from the robbery. At least 100 safety-deposit box owners did not claim insurance nor identify the items in the boxes.