Hugely significant, but somewhat overshadowed by the Labour re-shuffle shambles, was this week’s decision by David Cameron to allow his Ministers to campaign against the Government on the EU referendum when the time comes, without having to leave the Cabinet. This temporary suspension of the Cabinet principle of ‘collective responsibility’ was prompted by fears that not doing so would have caused either numerous sackings during the campaign or mass resignations beforehand. Rumour has it that the PM was bumped into announcing the decision now because of fears that Chris Grayling MP, the Leader of the House of Commons, was planning to quit over the issue as soon as this week.

The decision prompts even more parallels between Cameron and Harold Wilson, the last Prime Minister to allow Cabinet members to vote against the Government – also on the ever-thorny issue of the EU, or EEC as it was then. Reaction to his move has been mixed – some have branded it simply mad to sacrifice the power of a collective Cabinet voice on an issue of such national significance. But the reality is that the PM had no choice. Without this move, his Cabinet would have been obliterated by resignations sooner or later (or both). Importantly though, allowing his Ministers freedom on EU membership has bought him freedom too: Cameron will now be able to campaign for Britain to stay in the EU unencumbered by the need to placate the Eurosceptics around his top table.

Of course, this decision also opens the potential for a high-profile Minister to formally lead the ‘Out’ campaign, with Theresa May and Boris Johnson both tipped as candidates. The person this will really hurt, is George Osborne, who needs to improve his appeal with the party base if he is to succeed David Cameron as party leader. He is already being strategically outflanked to the right by May and Johnson on a whole host of issues. Arguing that the UK should stay in the EU – which, as Chancellor and close ally of the PM’s, surely he must – won’t help his popularity amongst the party base. Backed into such a corner, who knows what the Chancellor’s next move will be….