In 1974 you could tell a Labour politician from a Tory by the suit he or (less often) she wore.

Or as Labour’s chief whip says in James Graham’s new play, you can tell by the shoes visible under the doors of the Commons toilet cubicles — all the better to flush MPs out before a crucial vote.

There are only limited comparisons to be made between Labour’s hobbling minority government of 38 years ago and today’s limping coalition. But Graham, a hugely promising writing talent nurtured by Neil McPherson’s Finborough Theatre, certainly knows his political onions.

Jeremy Herrin’s gripping production reveals the sordid horse-trading behind cross-party deals and the ignoble tactics used to beat the “enemy”.

What a carry on our democracy is. What a bloody marvellous way to carry on. (Tel: 020 7452 3000)