Ed Davey will warn the Liberal Democrat faithful that the party is seen as “out of touch”, as he seeks to wean it off its passion for the European Union.
In his first conference speech as leader, party members – after three general election thumpings – will be told to “listen to what people are really telling us, and to change”.
While recent conferences have been dominated by the Brexit fight, Sir Ed is seeking to dilute the Lib Dem stance on rejoining the EU to merely an “option”, rather than a firm commitment.
Instead, he will use the virtual speech to pledge to “become the voice of Britain's 9 million carers”, setting out his own, sometimes difficult experience in that role.
The former cabinet minister in the Cameron-Clegg coalition nursed his mother through a long struggle with cancer, after his father died when he was four, and he has a disabled son.
“This is personal for me. You see, I’ve been a carer for much of my life,” Sir Ed is expected to say.
Describing his mother’s illness, he will say: “Taking her tumblers of morphine for her agonising pain, before going off to school. Coming home to look after her, helping her on and off the toilet.
“Taking life, day by day, because there was nothing else you could do. And at the end, visiting her on a totally unsuitable dementia ward in my school uniform, alone by her bedside when she died.”
Talking about his son, he will add: “John is 12. He can’t walk by himself. He was nine when he first managed to say ‘Daddy’. John needs 24/7 care – and probably always will.”
Sir Ed will say: “To all of you who are carers, to the parents of disabled children, to the thousands of young people, caring for your mum or your dad, I understand what you’re going through.
“And I promise you this: I will be your voice. I will be the voice of the 9 million carers in our country. It’s you I’m fighting for.”
The leader, who was elected last month, will say the party under him will always be “protecting civil liberties, championing the environment, patriotic, internationalist and, yes, always pro-European”.
But he will also tell members: “We have endured three deeply disappointing general elections, in five tough years. At the national level, at least, too many people think we’re out of touch with what they want.”
On Sunday, Sir Ed backed the Tory backbench revolt against the sidelining of MPs when Covid-19 restrictions are introduced, adding that his "only concern … is that it doesn't go far enough”.
In addition, he called for more “financial support" for students at university in the extraordinarily difficult circumstances of the pandemic.
Sir Ed said the disabled had been “failed” by the emergency coronavirus regulations, which are due to be renewed on Wednesday.
“People need that care, and for the government to legislate to take away rights to care, I think is outrageous.”