British director Mike Leigh has a unique way of making films. He gets a rough idea of a story line, then assembles a cast that he has improvise material in a rehearsal period that can last as long as six months. After that, he writes a script from what he discovers.

This process has given us some extraordinary characters and privileged moments in such award-winning films as "High Hopes," "Life Is Sweet" and "Secrets and Lies." It has also resulted -- within these same films -- in a fair amount of depressing tedium.

But with his new film, "Vera Drake," Leigh has struck gold. It recently took the top prize and best actress honors at the Venice Film Festival and its star, Imelda Staunton, has been proclaimed throughout the movie world as a sure-fire best-actress Oscar nominee.

His title character is a happy, well-adjusted wife and mother of North London in the year 1950, who works as a domestic in several households, takes care of her aged mother and does her own form of clandestine charity work by administering abortions to women who need them.

The entire first hour of the two-hour, five-minute movie is a chronicle of the rhythms of Vera's daily life: her employment situations; her relationships with her grown daughter and son, loving husband, in-laws and friends; and her secret life as an abortionist.

The second hour of the movie is taken up with what happens when one of Vera's young patients nearly dies, the police come and arrest her, and she and those around her (all of whom emotionally depend on her) have to deal with the tragic consequences.

Despite its hot topic, "Vera Drake" is hardly an issue movie. Leigh balances his abortion theme with subplots involving an unwanted pregnancy from a date rape and a much-wanted pregnancy in Vera's sister-in-law, but he doesn't express a strong opinion on the subject.

At their best, Leigh's movies are less about theme than about great scenes, and though his material is only an inch or two above soap opera, this one is alive with eerie moments of revelation and unexpected -- and often very pleasant -- twists of character.

For instance, the sequence in which Vera is taken to the local precinct and interrogated by a group of extraordinarily polite police goes against all the cop-movie clichés and is utterly mesmerizing in its sense of absolute veracity.

The film is also, of course, a character study and a star vehicle. And if Leigh's feelings about abortion are not entirely clear, it's very clear he considers Vera Drake a kind of saint (to the point of having a heavenly choir periodically burst forth on the soundtrack).

Indeed, she seems to be Leigh's version of Mrs. Miniver: the unpretentious woman who survived the Blitz, supports everyone around her with a stiff upper lip and acts out of a basic decency that is the best part of the British character.

And Staunton's portrayal of Vera is both flawless in every gesture and quite a bit more than the sum of its parts. There's nothing harder for an actor to play than a thoroughly good character, and Staunton does it with a dowdy, sublime originality.