Theresa May became Prime Minister within a few weeks of the British people voting to leave the European Union. She can be forgiven for needing a few months before she was ready to trigger the process of thrashing out how that would happen as she was starting from scratch.

Preparations have led to a great upheaval across Whitehall, with two new departments created to oversee the Brexit negotiations and the trade negotiations with nations outside of the EU. By March 2019, when Article 50 expires, the Institute for Government estimates that as much as £2 billion could be spent by officials on relevant work, which is somewhat understandable given the enormity of the process.

Their political masters have had to put in a lot of effort too. It's no small feat to have Liam Fox and Philip Hammond both agreeing with Mrs May that Brexit should mean things like leaving the Customs Union after a quasi-EU membership transition period. Those Chequers summits and Brexit "war cabinet" meetings have not been easy.

However, her former cabinet colleague George Osborne doesn't have much sympathy. He may have carried out as Chancellor a "serious amount of contingency planning" to ensure financial stability following a Brexit vote (which Mark Carney duly enacted), but no one considered under his watch how it would be delivered.