The Boris Johnson loyalist, who backed Truss during the leadership race, said she feared the prime minister was “lurching to the right” and abandoning the centre ground to the Labour Party.
Dorries told The Times: “I understand that we need to rocket-booster growth but you don’t do that by throwing the baby out with the bathwater. You don’t win elections by lurching to the right and deserting the centre ground for Keir Starmer to place his flag on.
“If we continue down this path, we absolutely will be facing a Stephen Harper-type wipeout. I’m sure she’s listened and will stop and rethink.”
Former Canadian prime minister Harper lost power to Justin Trudeau in the 2015 election after a decade of Conservative rule.
Dorries raised fears about rowing back from raising benefits in line with inflation – which would mean a real-terms cut in welfare for the poorest households during a cost-of-living crisis.
“It would be cruel, unjust and fundamentally unconservative,” she said.
She also renewed her warning that a radical departure from the 2019 manifesto – which helped Johnson secure a huge majority over Labour – would require another general election.
It’s the last sign of discontent within Tory ranks after the U-turn over plans to scrap the 45% tax rate for earnings over £150,000, tumbling poll ratings and the economic mess caused by the mini-budget.
HuffPost UK has reported that many angry Conservative MPs now want the government to stick by Johnson’s promise to raise benefits by the rate of inflation — something Truss and chancellor Kwasi Kwarteng have so far failed to do as they draw up plans to slash public spending.
During her keynote address at conference on Wednesday, Truss launched a furious attack on the “anti-growth coalition” she believes is holding Britain back.
The prime minister said opposition parties, trade unions, think-tanks, anti-Brexit campaigners and environmentalists had joined forces to block her attempts to grow the economy.
She hit out in a desperate bid to unite her party following days of bitter infighting in Birmingham.
In a defiant message to her critics, the prime minister insisted she was sticking to her economic growth plan.
She said: “We must stay the course. We are the only party with a clear plan to get Britain moving.
“We are the only party with the determination to deliver. Together, we can unleash the full potential of our great country.
“That is how we will build a new Britain for a new era.”