The senior MP, who chairs parliament's defence select committee but was stripped of the Tory whip in July, said the party should stick to its sensible and fiscally responsible roots.
He said that "haemorrhaging the one-nation voice" would lead to electoral disaster and called on the under-fire prime minister to "regroup very, very quickly" by bringing in the "full complement of talent".
As Truss prepares to give the closing speech at a Conservative party conference that has been plagued by divisions and several U-turns, she was urged by Ellwood to show humility and acknowledge that "some serious mistakes were made".
"She needs to be more inclusive, more open and transparent in where she wants to take Britain - reconfirming fiscal responsibility as the hallmark of where our party sits," he said.
Despite having not held the Tory whip for three months, due to not supporting Boris Johnson in a no-confidence vote because he was in Moldova, Ellwood said he absolutely still felt at home in the Conservative party. "If people like myself and those who are like-minded think about departing the party, where does that leave the party?" he said.
"It's the amalgamation of all the voices in the party that usually provides that moderate centre-right, sensible, fiscally responsible leadership that the nation then supports and elects.
"As soon as you start haemorrhaging the one nation voice of the party, we will not have that mass appeal. We will not be able to win elections because we will fail to secure support from the centre ground."
Ellwood said talk of immediately toppling Truss was premature, and she still had a chance to salvage her premiership by ensuring the chancellor's medium-term growth plan, pencilled in for 23 November, and Office for Budget Responsibility forecasts were brought forward.
This story is from the October 06, 2022 edition of The Guardian.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber ? Sign In
This story is from the October 06, 2022 edition of The Guardian.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber? Sign In
The Filter Cast-iron alternatives to Le Creuset for less
Le Creuset's colourful pans have long topped the wishlists of amateur and professional cooks.
Money hacks How to find a pet-sitter you can trust
Unless you have family, a friend or a neighbour who can care for your pet when you're away, you'll need to find a pet-sitter you can trust.
Pensions An A to Z of how to save for your retirement
Everything you need to know to plan for your future and make the most of your finances. Rupert Jones and Hilary Osborne report
'A fork in the road' AI's bid to help on laundry days at Europe's tech summit
This year's Web Summit in Lisbon was all about artificial intelligence and a robot sorting laundry.
Brexit So how could Labour improve EU ties for the sake of growth?
The Bank of England governor, Andrew Bailey, said this week that Brexit had undermined the UK's economy, and urged the government to improve relations with the EU for the sake of growth.
Aviation Flying taxis: destined never to take off?
In a dreary November day in the Cotswolds, the VX4 - a cross between a plane and a helicopter - rose from an airport runway, hovered a few feet off the ground and set back down.
Property firm back in profit as workers return to offices
One of Britain's biggest property developers has provided further evidence of the return to office working, saying occupancy in its central London offices is at an all-time high and the value of its portfolio has returned to growth.
Analysis Summer of dark warnings from the Treasury may have cast a shadow on growth
It was hardly surprising that the chancellor, Rachel Reeves, declared herself \"not satisfied\" with the news that the UK's GDP expanded by a measly 0.1% in the three months to September.
Contracting GDP adds to German woes as general election looms
Germany's looming general election will be fought against the backdrop of a stagnating economy, the European Commission has forecast, with GDP expected to have contracted in 2024.
UK economy slows amid jitters over Labour budget
The UK economy slowed to a near-standstill in the third quarter as uncertainty around Labour's first budget and high interest rates weighed on business and consumer spending.
