Mark Serwotka has an article in today's Guardian, which cuts through some of the more vapid arguments about unity:

We need unity. This is obvious, but it becomes controversial when concrete proposals are made. To build unity, you cannot accept that someone else's job is expendable or that someone else's rights should be lost. Unity requires solidarity – whether for students, pensioners, welfare recipients, or for public or private sector workers. I do not want to see a pick'n'mix approach to our opposition to the cuts, between "good" cuts and "bad" ones. This position is backed up with an economic case, published in our pamphlet, There is an Alternative.

That is essential. Don't try to buy credibility (with who? the media? the established parties?) by declaring someone else's jobs, livelihoods, and services, expendible. To buy into a 'credible' cuts agenda, or worse, 'progressive austerity', not only concedes unnecessary territory, it risks dividing the potentially broad movement against the cuts. This is simplicity itself, but apparently needs saying.