Writing for The Telegraph, Amanda Milling, Conservative Party co-chairman said the Tories would need to work hard to regain voters’ trust.
She wrote: “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 by-election result in Chesham and Amersham came as a major upset to the Tories who have owned the seat since its creation in 1974.
Lib Dem candidate, Sarah Green, annihilated her Conservative competition with a majority of over 8,000 votes.
The party’s leader, Ed Davey, hailed the victory as a “huge victory” for the Liberal Democrats.
He said: “We were told it was impossible for any party to beat the Tories here in Buckinghamshire.
Cabinet ministers have warned this latest election result was a “classic protest vote” to get the Government’s attention.
An adviser to a Cabinet Minister also told The Telegraph: “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.”
Another adviser added that “traditionally Tory voters” felt overlooked by the Prime Minister’s focus on Labour voters during last month’s Super Thursday by-elections.
He warned voters “feel like we’re not on their side.”