LONDON — Welcome to the U.K.’s permanent revolution.

Having won a referendum and an election, Boris Johnson and Dominic Cummings have turned their attention to overhauling the machinery of government.

Their plan? To centralize power in No. 10, improve efficiency and reduce the influence of a civil service establishment that Cummings likes to call “the blob.”

Whitehall’s top brass have been put — very publicly — on notice, with a briefing from “senior Tories” to a Sunday newspaper that three heads of department are on a No. 10 “hit list.” The Home Office has been rocked by briefings and counter-briefings about boiling tensions between Home Secretary Priti Patel and her top official Philip Rutnam.

Meanwhile, the ranks of special advisers — who provide media and policy support to ministers — have been purged of those not regarded as sufficiently loyal or useful to No. 10. That brought even the powerful Treasury to heel as Chancellor Sajid Javid opted to quit rather than see his team replaced.

Downing Street’s goal is as much about reforming the machinery of government as it is about ideology.

But while the approach is winning support among the Conservative party’s victorious Brexiteer faction — who have long-regarded the civil service as a bastion of pro-EU thinking — others warn of the danger of having perpetual campaigners at the heart of government: they might prevent people actually governing.

“It's not normal for three permanent secretaries to be described as being on a hit list on the front of the Sunday Telegraph,” said Alex Thomas, a former senior Whitehall official and now a program director at the Institute for Government think tank. “[It] doesn’t feel like the way to win hearts and minds within the system, and you’re then likely to get more resistance [from officials].”

According to one former senior government official, Johnson and Cummings “are setting up some problems for themselves.”

“The danger is that a culture emerges where everyone is afraid to make their own decisions because they’re afraid to mess up and incur the wrath of Dom,” the official said.

Brexiteers vs. Mandarins

Downing Street’s goal is as much about reforming the machinery of government as it is about ideology.

Cummings has long advocated a pared-back, more nimble civil service, more accessible to talent from a more diverse range of disciplines. His view, as articulated on his blog, is that there are "profound problems at the core of how the British state makes decisions" and this will need to change in order to make the most of the opportunities and challenges presented by Brexit.

And with potentially five years until the next general election, the new occupants of No. 10 have time and political capital to spend on a shakeup.

But today's tensions also have their roots in a deep suspicion of the civil service that permeated Brexiteer opinion during the Theresa May era, when powerful officials like Olly Robbins were accused of wanting to keep the U.K. closely bound to EU rules.

Now that many of those same Brexiteers are in power, a clash was inevitable. One of the senior officials on the "hit list" reported by the Sunday Telegraph was chief civil servant at the Treasury, Tom Scholar, targeted, according to the paper's source, for the crime of being “off-side” on Brexit.

“Senior officials in Whitehall despise Brexit,” claimed one former Cabinet minister, now on the Conservative back benches. "No. 10 has strong support among Brexiteers in its efforts to cleanse Whitehall’s Augean stables."

While some of the rhetoric has echoes of Donald Trump’s “drain the swamp” mantra, battles between U.K. politicians and their civil servants are nothing new. Tony Blair's Labour government quietly saw to it that a number of permanent secretaries were moved on, and reforming ministers rarely encounter an entirely pliant department.

Mark Sedwill, the Cabinet secretary and head of the civil service, on Monday sought to draw a line under the tensions with an email to all civil servants.

Nevertheless, many observers have been struck by the “revolutionary zeal” of recent briefings against officials.

The question is how effective the strategy will be. “Cummings is always looking for an enemy," said another former government official, speaking on condition of anonymity. "It was the EU in the Brexit campaign, in the last parliament it was those blocking Brexit. He is desperately looking around for a new enemy, but that doesn’t really work in government.”

'Keep them on their toes'

The top ranks of Johnson's team and the civil service both say they are now seeking a truce.

Mark Sedwill, the Cabinet secretary and head of the civil service, on Monday sought to draw a line under the tensions with an email to all civil servants (but clearly aimed at ministers too) warning that "unattributable briefings and leaks to the media" harm the U.K.'s "hard-won reputation for good governance" while adding pointedly that "the whole civil service is committed to delivering the government's agenda."

After a feverish few days, No. 10 officials also indicated a willingness to de-escalate.

A Home Office spokesperson issued a joint statement from Patel and Rutnam condemning anonymous briefings (to the Sunday Times) that MI5 officials were withholding information from the home secretary.

But some observers believe the fault lines are here to stay. The former senior official speculated whether Cummings might find the current tensions a useful way to keep civil servants "on their toes."

"That is definitely how he operates," the official said.

“There is definitely a stronger approach, a very 'get things done' mentality," added a former government special adviser. “The Cameron and the May administrations were not massively different in the way they treated the civil service. This one is very different. It’s adapt or die."

Annabelle Dickson contributed reporting.