The political settlement is changing. Labour is going through convulsions and contortions and by the end of the week the Conservatives will be well on their way to choosing a new leader. In the meantime the existing government carries on in office but lacking authority and momentum. The speed at which the energy and direction of the government has dissipated is extraordinary. Behind the scenes the senior civil service is speedily preparing for a new Prime Minister and their new administration. We have had in effect a General Election in all but name.

That Brexit is the new national policy is beyond question. What that looks like will in part be hammered out in the pressure of the Conservative leadership election. It will be further refined when the new leader is installed in No 10. Not everyone will be happy. New leaders usually end up disappointing their followers to some degree in the end. The more fervent the supporter the more acute is usually the disappointment.

In the meantime there are certain practical questions that need to be addressed. What are called machinery of government issues are ones Prime Ministers go out of their way to avoid. They are usually unhappy experiences and take much longer than anticipated to bed down and settle in. David Cameron let it be known before coming to office he planned no such changes. He was determined not to become bogged down in the bureaucratic quagmire of Whitehall. In any case he needed all the places around the Cabinet Table he could squeeze in to reward followers, appease the Liberal Democrats and then from 2015 onwards to bind as many people in as possible.

Since the cuts in civil service numbers have kicked in the fact many departments have reduced significantly in size and in reality capacity. The hollowing out of departments has been real and brutal. It has come though with no corresponding reduction in the number of departments, Secretaries of State or junior Ministers – of which there are 109 in 24 departments.

In effect central government has become like a great mushroom cloud floating over Whitehall  – bloated at the top and shrivelling underneath. Each Minister is serviced by an outer office and all the apparatus that such exalted status demands. Changes were desirable in 2010. Post Brexit they are essential. It is time this cloud was blown away.

A new government needs a new reformed machine to deliver its priorities. There will be a new EU relations department, probably headed up by a Cabinet Minister. An effective trade department has long been required, and is now an absolute necessity. Cutting the cost of central government has probably gone as far as it reasonably can in the existing structures. The new Prime Minister will spend a huge amount of their time on EU issues, managing their party and a fractious Parliament. They will be abroad championing trade deals – and then there is the daily dealing with security issues which takes place out of sight but occupies more time than most appreciate. It seems likely therefore a deputy will be needed to run the government day-to-day to ensure the Prime Minister’s writ runs through Whitehall and the domestic agenda is fulfilled.

The autumn will also see the most significant Budget in a generation. George Osborne has hinted at some of the measures to come. A new government will have to significantly realign tax and spending priorities. No department will be immune. No currently agreed settlement will stand untouched. The Treasury is facing a huge challenge.

In the way he organised No 10 and the Cabinet Office David Cameron told friends early on in his Premiereship that he had in effect created a Prime Minister’s Department without anyone noticing it. Key to the success of the new Prime Minister will be to take a firm grip on these two centres of operation. So much more could have been achieved by David Cameron if the operation in No 10 and the Cabinet Office had been better organised. Ensuring this operation is properly established is key to the success of the new administration.

Fewer departments each with a sharper focus is required. This is a big task to take on on-top of everything else. It is however absolutely necessary. Whitehall’s current settlement is creaky, lacks coherence and is overly bureaucratic. New policy needs to be driven by a new Whitehall.