SEXUAL tension courses through the small law firm in John Van Druten’s meaty slice of workplace politics as strongly as the dirty water of the nearby Thames.

It is 1931 in London Wall and women are a relatively new addition to the workplace, with both sexes struggling to make the adjustment.

The oily Mr Brewer, convinced he is God’s gift to women, cannot believe his luck.

He prowls the corridors of Messrs Walker, Windermere and Co in search of what he sees as fair game, and when 19-year-old Pat Milligan joins the typing pool he soon has her in his sights.

Frustrated by the lack of attention from dull, but reliable Hec, who works in the office upstairs, she begins to fall for Mr Brewer’s unctuous charms despite her colleagues’ warnings.

Fellow typists Miss Janus and Miss Hooper are both growing increasingly desperate for their men to put a ring on it and throw them a lifeline out of the office.

Meanwhile, flirtatious Miss Bufton relishes the attention of her many suitors and the roguish young office assistant Birkinshaw looks dangerously poised to become Mr Brewer’s protege.

Their imperturbable boss Mr Walker lets it all flow round him, as the eccentric dowager Miss Willesden hovers on the periphery, destined to have her say on proceedings.

Van Druten’s study of sexual politics is still relevant but feels comfy, rather like Mad Men with its breeches pulled up, or Downton Abbey, where the landed gentry are forced to find work.

There is something of the Blitz spirit among the young typists, who are all in it together as they plot their way through the sexual minefield.

Each encounter is like a life-or-death scouting mission and every time they leave the office it is as if they are heading to the front line, from which they may never return.

Director Tricia Thorn’s lively production captures the dynamics of a busy, but claustrophobic law firm, and Van Druten’s dialogue is frequently both as witty and deadly as a volley of gunfire.

It is somewhat ironic that this 30s play about women struggling to make their way in the workplace offers juicier female roles than many modern shows.

As Miss Janus, desperate for a husband at the ‘ancient’ age of 35, Alix Dunmore makes the most of the opportunity.

While some of the acting is a touch hammy, she subtly portrays this elder stateswoman of the office as a thick-skinned pragmatist, who thinks she has it all worked out, but is just as vulnerable and confused as young Miss Milligan.

Unfortunately, the plot is as predictable, to go all Jeremy Clarkson on you, as a French surrender. It is as if Van Druten pulled back from the scathing expose of workplace sexism this threatened to be and settled for something cosier but nonetheless enjoyable.

London Wall is at the Finborough Theatre until Saturday, February 23. Tickets are available at www.finboroughtheatre.co.uk or from the box office on 0844 847 1652.