The film tells the story of Hortense Cumberbatch, a successful black middle class optometrist in London, who is adopted and has chosen to trace her family history after the death of her adoptive mother. After being warned by public officials about the troubles she could face by tracking her birth mother down, she continues her investigation and is baffled to learn that her birth mother is white but does not resent her and wants to know more about her past. Her birth mother, Cynthia Purley, is working class and downwardly mobile. Hortense meets her and later meets Cynthia's brother, Maurice Purley, a photographer, his wife Monica, and Cynthia's daughter Roxanne, a street cleaner.
At the Purleys', it is evident that severe tensions exist between Roxanne and her mother. Both are frustrated with one another and getting on one another's nerves. Maurice and Monica also experience domestic tensions. Monica comes across as abrupt, but later scenes reveal that she suffers from severe menstrual cramps and Monica makes concerted efforts to placate matters and be contrite. Things are also not well between Maurice and his sister, they are a bit awkward with one another but both look forward to celebrating Roxanne's birthday. Cynthia refers to Maurice affectionately as her little brother and asks him as she always does when he is going to shave. It is clear that Cynthia somehow can survive by the money she receives from Maurice.
Hortense rings Cynthia and asks for a 'Cynthia Rose Purley', and starts talking about a baby called "Elizabeth Purley", born in 1968. Cynthia realises that Hortense is her daughter whom she gave up for adoption and hangs up the phone. Hortense is still determined to find out more about her background. She rings Cynthia again and manages to convince her to meet with her. When they finally do, Cynthia feels that a grave mistake has been made. Hortense convinces Cynthia to have a cup of tea. Hortense asks Cynthia to look at a document; she then begins to cry and then states that she is ashamed. Hortense then wants to know who her father is, to which Cynthia refuses to answer.
After a while Hortense and Cynthia have struck up a friendship, which is somewhat noticed by Roxanne after seeing her mother going places but not knowing where, since Cynthia is rather secretive about it. Cynthia mentions the birthday party for Roxanne and also gives Hortense a gift. Cynthia asks Maurice if she can bring a "mate from work" to Roxanne's party. Cynthia relays this information to Hortense who replies that she would feel a bit awkward. Despite these feelings, she agrees to attend and pose as a colleague from work. The day of the barbecue arrives and Monica makes an effort for everyone to feel welcome. Cynthia makes incisive remarks in passing, but making sure that Monica hears them, about the seemingly high expenses that she makes in her house instead of concentrating on giving Maurice a child. Maurice tells Roxanne that she has a good brain and should be in college. Roxanne does not take this suggestion seriously. Everyone gathers for the barbecue and Maurice prepares the food. During the meal Hortense answers many questions which are naturally put to her by the other guests. Hortense says that she is pursuing medical research and endeavours to be evasive. Also present at the barbecue are Maurice's assistant Jane and Roxanne's boyfriend Paul.
When Roxanne blows out her birthday candles Cynthia begins to act in an exceptionally nervous manner. She states that Hortense is her daughter. Everyone dismisses this claim and states that she has had too much to drink. However, when Monica inadvertently confirms this as true, Roxanne is horrified and storms out of the house. Maurice attempts to placate matters by confronting Roxanne at a nearby bus stop. He attempts to convince Roxanne to speak to her mother again and Cynthia apologises to her profusely. Cynthia then explains that she got pregnant at fifteen and her father sent her away due to feeling shame over her pregnancy and after the adoption she never expected Hortense to come back. Cynthia then accuses Monica of being selfish. Maurice reveals that Monica is physically incapable of having children. Maurice then loses his temper and states that he has spent his whole life trying to make people happy and that he cannot take it any more because the ones he loves most "hate each other's guts". After witnessing all this Hortense tries to leave but Maurice stops her, admiring her courage for trying to find her own past, although he will not reveal who her father was either. Cynthia then explains that Roxanne's father was an American medical student vacationing in Benidorm. One morning in Benidorm, Cynthia awoke and he had gone.
After a while things have calmed down and Hortense is free to visit Cynthia and Roxanne at their home. Hortense reveals that she always wanted a sister. Roxanne reveals that she would be happy to introduce Hortense as her half-sister notwithstanding the long explanations that it would entail. They gather for a visit at Cynthia's, and have tea.Timothy Spall as Maurice Purley
Brenda Blethyn as Cynthia Rose Purley
Phyllis Logan as Monica Purley
Marianne Jean-Baptiste as Hortense Cumberbatch
Claire Rushbrook as Roxanne Purley
Elizabeth Berrington as Jane
Michele Austin as Dionne
Lee Ross as Paul
Lesley Manville as Jenny Ford, the Social Worker
Ron Cook as Stuart
Emma Amos as Girl with Scar
Brian Bovell and Trevor Laird as Hortense's Brothers
Clare Perkins as Hortense's Sister-in-Law
Jonny Coyne as Fiancé
Leigh was inspired by "people close to [him] who have had adoption-related experiences" to make a film about adoption. Speaking on the subject, he stated: "I wanted for years to make a film which explored this predicament in a fictitious way. I also wanted to make a film about the new generation of young black people who are moving on and getting away from the ghetto stereotypes. And these were jumping off points for a film which turns out to be an exploration of roots and identity."
Many Leigh regulars appear cameo appearances in the film, most of whom serve as clients at Maurice's job, including Peter Wight as the father in a family group, Gary McDonald as a boxer, Alison Steadman as a dog owner, Liz Smith as a cat owner, Sheila Kelley a fertile mother, Phil Davis as a man in a suit, Anthony O'Donnell as an uneasy man, Ruth Sheen as a laughing woman, and musician Mia Soteriou as a fiancée.
Secrets and Lies was partly filmed in Whitehouse Way, Southgate, London. Although Leigh is credited with writing the screenplay, most of the performances were improvised: Leigh told each of the actors about their roles, and let them create their own lines. The emotional scene in the diner, in which Cynthia realises that she is indeed Hortense's mother, was filmed in a single uninterrupted take of a little more than 7 minutes. Brenda Blethyn was not told beforehand that Hortense was black, making her reaction in this scene more authentic.
The film was released to universal acclaim; review aggregator website Rotten Tomatoes reported that 94% of critics gave the film a positive rating, based on 36 reviews, with an average score of 8.7/10. On Metacritic, which uses a normalised rating system, the film holds a 91/100 rating, based on 27 reviews, indicating "universal acclaim".
Influential film critic Roger Ebert, writing for the Chicago Sun-Times gave Secrets & Lies four out of four stars. He wrote that "moment after moment, scene after scene, Secrets & Lies unfolds with the fascination of eavesdropping", and added: "[Leigh] finds a rhythm of life – not 'real life,' but real life as fashioned and shaped by all the art and skill his actors can bring to it – and slips into it, so that we are not particularly aware we're watching a film." He called the film "a flowering of his technique. It moves us on a human level, it keeps us guessing during scenes as unpredictable as life, and it shows us how ordinary people have a chance of somehow coping with their problems, which are rather ordinary, too." In 2009, he added the film to his "Great Movies" list.
Edward Guthmann of the San Francisco Chronicle called the film Leigh's "best and most accessible work to date" and remarked that "everyone's had these family skirmishes and confrontations in their lives, and it's remarkable to see them recorded so accurately and painfully on film. Leigh's marvelous achievement is not only in capturing emotional clarity on film, but also in illustrating the ways in which families start to heal and find a certain bravery in their efforts." Similarly, Kenneth Turan from the Los Angeles Times ranked the film within "the best of the 14 features Leigh" had directed by then. He found that Secrets & Lies was "a piercingly honest, completely accessible piece of work that will go directly to the hearts of audiences who have never heard of him. If film means anything to you, if emotional truth is a quality you care about, this is an event that ought not be missed [...] Unforced, confident and completely involving, with exceptional acting aided by Dick Pope's unobtrusive camera work and John Gregory's telling editing, Secrets & Lies is filmmaking to savor."
The Washington Post author Desson Howe felt that the film incorporated all the "elements of humor, sweetness, cruelty and directness" of Leigh's previous films but dubbed Secrets & Lies "more emotional, tear-inducing and compassionate than its predecessors." He declared it "an extended, multilayered revelation, and you don’t get the full, complex picture until the final scene." His colleague, Rita Kempley, called the film "a magnificent melodrama that draws both tears and laughter from the everyday give-and-take of seemingly ordinary souls." She noted that "Blethyn and Jean-Baptiste are a joy to behold in tandem, but Blethyn's endearing portrait is transcendent."
It is also listed as the 40th best British film by the BFI.
This film was the subject of "positive pickets" by the adult adoptee rights organisation Bastard Nation, which used it as a vehicle to raise awareness of sealed birth records in the United States and Canada. (See No More Secrets and Lies: Bastard Nation's Positive Picket (November 1996 – March 1997)
Director Leigh and actress Blethyn met with Bastard Nation activists at a positive picket in Beverly Hills on 10 March 1997, where they were presented with Bastard Nation T-shirts.