The manicured mercenaries with Sly in their sights

Move over, macho men. Here come the ExpendaBelles

Picture the scene. Sigourney Weaver is back as Ripley, ready to pulverise some aliens. As she pulls on her spacesuit another figure, in yellow, emerges. Why, it's The Bride from Kill Bill! Moments later, a shriek of laughter is followed by the arrival of three girls, demanding an audience with someone called Charlie. Ripley and The Bride look at the new arrivals with disdain. This, ladies and gentlemen, is ExpendaBelles.

At least, it could be. Following the box-office success and probable third instalment of The Expendables film franchise, whose ensemble casts have brought together classic Eighties action stars including Sylvestor Stallone, Dolph Lundgren and Jean-Claude Van Damme (film number two came out in August this year), there are now not one but two spin-offs in the works, both set to replace Sly and his crew of beefed-up mercenaries with, wait for it, women.

One, ExpendaBelles, has signed the writers behind the frothy romcom Legally Blonde, in a move that has left fans wondering what to expect. Girls with guns in pink? It hardly sounds like Rambo. The other, as yet untitled, film seems to be on a grittier trajectory. It has cast action-gal staple Gina Carano, seen recently in Haywire, to star, with producer Adi Shankar claiming in an interview that making a female version of The Expendables without Carano "would be like making Twix without caramel".

The popularity of The Expendables, though, was rooted not so much in its action sequences as the familiarity of the stars themselves and their extraordinary assembly in one story. Arnold Schwarzenegger, back from retirement to shoot the breeze, and the bad guys, with Bruce Willis – it was the stuff fanboy dreams are made of. Like The Avengers, with a lot more testosterone.

ExpendaBelles, green-lit by the studio behind The Expendables, Millennium Films, intends to do the same thing but with women, according to Hollywood website Deadline. It will, the site claims, "be driven by actresses who've logged time in action films over the years". Millennium has not yet confirmed their plans for the plot or cast but the internet is awash with speculation over who those actresses might be. Angelina Jolie (Lara Croft) and Cameron Diaz (Charlie's Angels) are names that crop up frequently. Milla Jovovich (Resident Evil), Linda Hamilton (Sarah Connor in the Terminator films) and Brigitte Nielsen (Red Sonja) are popular too. And how about Kick-Ass's Hit Girl or Crouching Tiger Hidden Dragon's Michelle Yeoh? Even Helen Mirren gets a look-in.

The producers of each film will need to decide precisely who their audience is, says Gladys L Knight, author of the book Female Action Heroes. Eighties film buffs looking for a nostalgia fix? Or Charlie's Angels fans looking for camped-up comedy with some martial arts moves thrown in? Will the gals be sexy tough (Lara Croft) or scary tough (Sarah Connor)? Is sexy tough even an option if older actresses are used?

Part of the problem is that female action heroes do not have as clear a legacy or audience as men. Until Ridley Scott's Alien in 1979, when Weaver's Ripley made central female characters a viable alternative, women had mostly appeared on screen in order to be rescued. Even since then, Knight argues, there have been myriad versions of the female hero – from regal Princess Leia to the giggly Powerpuff Girls – while the role of the macho male has remained largely constant.

"The question is," says Knight, "does the contemporary female action hero now have to shave her head like the protagonist in G.I. Jane and remove all symbols of her femininity in order to be accepted?"

Do we believe, in other words, that women delivering killer lines and successfully deploying AK-47s should not be getting manicures?

Not for long, presumably, if the Legally Blonde team have anything to do with it.