In 1918 after a long and sometimes bloody campaign, women in England finally succeeded in winning the right to vote with two important caveats (they had to be 30 years of age or over and own property).

They would have to wait until 1928 for women over 21 to vote in England. It's disgraceful isn't it? That women, half the human race, had to live in a world where their fathers, husbands and brothers made the law and laid down the law too. For most of history they didn't have a say themselves.

It's sobering to think it hasn't even been 100 years since they finally won. In Saudi Arabia in 2015 women are still not allowed to vote, so it's still too early to pat ourselves on the back for a world transformed by justice.

It's a cause for celebration that director Sarah Gavron’s Suffragette, a film about the struggle to win votes for women in England, is pulling in huge box office numbers in the U.K., and also in the U.S. where it’s in limited release.

Starring Brendan Gleeson, Carey Mulligan, Helena Bonham Carter and Meryl Streep, it would appear that strong word of mouth is driving audiences to the theaters to catch this inspiring tale.

First the good news. Suffragette benefits from a wonderfully convincing central performance from Mulligan, a gifted young actress who dives into the material as if her life depends on it (and for her character Maud Watts it frequently does).

Mulligan simply carries the film from the opening scenes as an exploited washer woman whose political awakening has profound and tragic consequences for her both marriage and her son, but her journey from lowly drudge to political activist is at all times convincing and heartfelt.

The bad news is that neither the director or the screenwriter Abi Morgan quite trust their audience enough to grasp the sobering cost of women's struggle through their characters alone. Instead we witness set piece after set piece involving famous historical personages, all filtered through Edwardian social views.

Into this mix comes Streep as Emmeline Pankhurst, the militant activist who has decided that asking nicely has gotten her organization precisely nowhere. If you want your equality you will have to fight for it, she counsels her supporters.

In fact Streep barely clears her throat before she's ferried off screen again in a short but effective barnstormer cameo that the film's posters would seem to suggest would be much more substantial.

It's Gleeson who does the most interesting work in the film. Playing Inspector Steed, a secretive Irish police agent who pursues the suffragettes as if they were the mafia, he's a fascinating mix of insider and outsider whose ultimate aims are hard to fathom.

Steed believes that the natural order sees men call the shots and women take the orders. We learn that he has also spied on and betrayed Irish Republican cells in England. Clearly he believes that the right people are all in power, and he should work to ensure the wrong people never come to power themselves.

As Watt's main opponent this is an interesting clash of ideas and passions, but his character is never given the scope to really take off and neither is Mulligan's. Instead we see Maud tag along while other people take action and she accompanies them.

In the film's tragic and shocking denouement she has little to do but follow after the much more militant Maggie Miller (Grace Stottor) as she makes a gesture the writer's won't allow their main character.

The camera work in the film, with its shaky hand held or out of focus sequences, is a distracting nuisance. The intention is to generate a sense of drama, but audience members might find themselves making mental notes to make an appointment at LensCrafters.

Suffragette is a good film and an important one. It just isn't the great film its top tier actors deserve it to be.

They're underserved by a fairly route movie of the week structure that takes no narrative risks. With material this provocative and incendiary, it's remarkable to think that anyone would ever opt to play it safe, but unfortunately they have.