Just 15 months ago I spelt out in an article for Public Finance how much of strain trying to stick to Cabinet ‘collective responsibility’ would put on the Coalition government. I suggested that the Coalition would have to come up with some way of ‘agreeing to disagree’ as coalition governments elsewhere in Europe manage to do.

The eruption of disagreements between Coalition parties has come rather earlier than I expected, as the pressures of government have intruded into the heady, optimistic, early days of the Cameron-Clegg ‘bromance’.

The most sharp, and real, disagreement to date is the spat over new security legislation allowing Government access to ISP’s data flow records (Tim Farron says Lib Dems would ‘kill’ web monitoring plans).

Interestingly the other big fault-line in modern British politics – that between an overly powerful Treasury and the PM’s Office – is also surfacing as tensions start to emerge between David Cameron (PM) and George Osborne (Chancellor) (see Andrew Rawnsley’s analysis in today’s Observer). Whilst Rawnsley focuses on the politics, I would add that the position of HM Treasury, and the Chancellor, is in an unusually strong position as a combined economic and finance ministry.

After two very bad weeks, since the mishandled Budget, the strains are beginning to show.