Party, Assembly @ George Street, Edinburgh

As all budding politicos and wonks know, changing the world is fraught with pitfalls. First, you have to decide your stance on an entire spreadsheet of "issues" from the congestion charge to China, then there's the minefield of choosing a colour for your posters, not to mention the endless potential for gaffes involving un-fair trade coffee and the pronoun "they".

These and many other thorny problems are raised in Party, a hilarious new play written by Tom Basden – if.comedy Best Newcomer in 2007 – and performed by a superb cast of new talents.

In a suburban garden shed five friends are forming a new political party, working out what they stand for ("So we're all in favour of China and Muslims?"), getting to grips with the vernacular of bureaucracy and arguing over when to break out the lemon drizzle cake.

There's Jared, nice-but-dim, and, since it's his parents' shed, self-appointed leader (Jonny Sweet, a dead ringer for David Cameron who has just been cast to play the Conservative leader in a television drama about his early years); Mel (Anna Crilly), a strident liberal with strongly held beliefs but dangerously little knowledge; Phoebe (Katy Wix), secretary and sort of feminist; Jones, a highly competitive soul with one eye on the leadership (Basden); and Duncan (wonderfully deadpan Tim Key) who thought he was coming to a party, not to a Party and doesn' really understand what all the talking and voting is about.

Basden's deftly written script injects new life into the hoary old genre of political satire and the excellent quintet deliver it with perfect timing. There's an joyous debate over the party's name - '"Peace in the Middle East Party." What if there's peace?" "Then everyone will think it was our idea,"' and an absurd climactic scene on the perils of democracy. Brilliant.

To 31 August (0131-623 3030)