Boris Johnson has been told to pay more attention to "traditionally Tory" values by ministers after the shock Chesham and Amersham by-election defeat.

Cabinet colleagues are urging the Prime Minister to adopt a more "Tory-focused approach" and not take for granted the party’s traditional support base in the rural South, after losing a seat they held for almost half a century.

Around 100 Conservative MPs, including ministers, are now plotting to water down Mr Johnson’s planning reforms, which will loosen restrictions to build more houses, after a backlash to the changes from Chesham voters.

In an article for The Telegraph, Conservative Party co-chairman Amanda Milling said the concerns over "planning and HS2 were loud and clear". 

She writes: "I am in no doubt that Thursday’s result is a warning shot and we are listening. And as co-chairman, I will ensure that we learn the lessons from this campaign.

"Over the coming weeks and months, we will take stock of what happened in Chesham and Amersham and look at how we can regain the trust of voters there."

The intervention came after the Liberal Democrats claimed the constituency by 21 percentage points, despite the Tories winning the seat by 29 points in December 2019, a remarkable swing away from the Conservatives.

Liberal Democrats win in Chesham and Amersham

Red Wall obsession

The defeat sent shock waves through the party, raising fears that in reaching for heartland Labour Red Wall seats in the North, Mr Johnson had neglected rural Tories.

A Cabinet minister told The Telegraph: “This was your classic protest vote. The message to Government was ‘oi, listen to us. We’re still here and you should care about us’.”

Other ministers have long been urging for a return to the Thatcherite values of fiscal conservatism and a smaller state following the vast increases in public spending seen as the Government propped up the economy during the Covid-19 pandemic.

An adviser to a Cabinet minister said: “People are thinking that the Government is all about the Red Wall. ‘How is this going to play in the Red Wall seats, what is the Red Wall thinking?’

“Whereas the Red Wall is actually very small. It is not the biggest bit of our base.”

A second Cabinet adviser said “traditionally Tory voters” felt overlooked by the focus on former Labour voters, warning that “they feel like we’re not on their side”.

The defeat triggered renewed calls from Tory rebels for a rethink on the Government’s planning reforms after widespread reports the changes were a critical factor in the Chesham defeat.

Disgruntled MPs join WhatsApp group

The Telegraph has been told “nearly 100” Conservative MPs, including Cabinet ministers, are part of a WhatsApp group titled “Planning Concern” to air their grievances on the reforms.

The rebel Tories want the Government to bring in a so-called greenfield tax on developers, which would pay for brownfield sites to be cleaned up and so encourage more building.

The scale of the potential rebellion will alarm Downing Street. It is more than a quarter of all Tory MPs and well beyond the 40-odd rebels needed to potentially defeat the Government.

Amersham election historical results

Writing for The Telegraph, one critic of the planning reforms, Theresa Villiers, a former Cabinet minister and MP for Chipping Barnet, said: "This by-election result should pave the way for a reduction in housing targets for the London suburbs and the South East.

"We need a fairer distribution of new homes across the country, rather than seeking to cram so many thousands more into the crowded South. There needs to be a stronger focus on brownfield sites in urban inner city areas."

Mr Johnson has admitted the Chesham result was “disappointing”, but defended his electoral strategy and vowed to push on with the biggest planning shake-up in 70 years.

Lib Dems accused of promoting ‘wilful misunderstanding’

The Prime Minister accused the Lib Dems of pushing a “wilful misunderstanding” of his planning reforms, saying: “I do think that young people growing up in this country should have the chance of home ownership.”

He also repeated his vision of “one-nation Conservatism”, arguing: “We believe in uniting and levelling up within regions and across the country.”

But the Lib Dems have made clear their determination to go after the traditional bedrock of Tory support in the South, with a list of 10 new Tory seat targets shared with The Telegraph. 

Sir Ed Davey, the Lib Dem leader, celebrated victory by literally knocking down a blue wall, representing the Tory heartlands, with an orange hammer as the TV cameras rolled.

Sarah Green, the Lib Dem candidate, won Thursday’s Chesham and Amersham by-election with around 57 per cent of the vote, compared to 36 per cent for Tory Peter Fleet. The Tories have held the seat since its creation in 1974.

Conserative MPs who campaigned there said criticism of planning changes and HS2 were mentioned repeatedly by voters.

Mr Johnson has had striking electoral success by appealing to working class communities in the North East and Midlands that have traditionally voted Labour.

His success winning over voters in the Red Wall seats, in part because of Brexit, helped secure him a 80-seat majority in the Commons in the December 2019 general election.

However, the Chesham defeat has reignited fears that by spending political capital appealing to former Labour voters, the Government has weakened its connection to the traditional bedrock of Tory support in rural southern constituencies.

Earlier this week, Lord Frost, the Brexit minister, warned against the “intellectual fallacy” that a “big state” and high public spending levels lead to sustainable economic growth.

Meanwhile, Rishi Sunak, the Chancellor, has indicated his desire to get public spending back under control, warning in a Yorkshire Post interview that he couldn’t “just say yes to everybody who comes knocking on my door”.