Repeating History

The New Politics is seemingly hovering around the idea of several not-actually-so-very-different-now-they-think-about-it parties coming together to form an anti-Tory super-organism composed of Labour and some phantom limbs. The not-the-Tories party refers to itself as the 'progressive alliance', but since I don't know what 'progressive' means, let's call them the Whigs for short.

Update: phantom limbs indeed... According to this, the Lib. Dems. are saying that 'the Labour Party never took seriously the prospects of forming a progressive, reforming government'. So whoever are the progressive ones?