Boiling Frogs uphold their reputation as the coolest company around

Is The Factory the best-connected young theatre company in town? Their upcoming production of Boiling Frogs comes with the stellar backing of Mark Rylance, Tracey Emin and Ewan McGregor.

McGregor, who last week hosted a fundraiser for the company, has been a supporter since 2008 when artistic director Alex Hassell bumped into the film star at Shakespeare's Globe, and invited him to see their deconstructed, pop-up Hamlet.

Intrigued by the promise of a production in which the audience chooses which actor plays which part and provides the props, McGregor showed up on a Sunday afternoon with an accordion under his arm. He was duly pulled up on stage and serenaded by Hamlet before being eclipsed by a newborn baby, plucked out of an audience member's arms to act as a live prop for the Dane's "What a piece of work is man" speech.

Since then, Josh Hartnett, James McAvoy and Rufus Sewell have all dropped in for guerrilla performances (usually playing the undemanding Fortinbras). "We've just whipped them in when they've been around. If we spot them, we just shove a script in their hands," says producer Liam Evans-Ford.

In the meantime, Hamlet has become a must-see hit, selling out secret performances in pubs and backstage at theatres and drawing crowds at summer festivals. They've since tackled Chekhov's Seagull and this year have been experimenting with new-writing in Round 2, a series of half-hour "bouts" of six hot-off-the-press playlets.

Boiling Frogs represents a new direction – their first full-length new play, and the first time they'll take up residence in a theatre, instead of sneaking around in the bar or the car park on a Sunday afternoon. Steven Bloomer's satire, inspired by the picnic protests in Parliament Square, is a fierce dissection of the erosion of civil liberties. Being The Factory, it's still not quite theatre as we know it – each character is played by two actors while a unique flatpack design comes courtesy of the graffiti artist Pochoir ensuring they uphold their reputation as the coolest company around.

14 September to 2 October, Southwark Playhouse, London SE1 (0207 407 0234; www.southwarkplayhouse.co.uk)