Ed Miliband has joked that he helped write Theresa May's Tory conference speech in which she railed against corporate greed, backed state intervention and suggested she would end abuses in the energy sector.
The former Labour leader praised Mrs May for understanding the Brexit vote represented a "deep dissatisfaction" with the country but said he would judge the Prime Minister by her actions.
Cabinet ministers and aides to Mrs May were forced to reject comparisons with Mr Miliband after her speech to the Conservative Party conference in Birmingham.
Mr Miliband made inequality a central theme of his eventually unsuccessful leadership, promised action to freeze energy bills and described Britain as a country that works for the "privileged few".
In her conference speech, Mrs May said Britain works "for a privileged few but not for ordinary working class people", told the wealthy "elite" she was "putting you on warning", and suggested energy customers were being treated unfairly.
Commenting on the speech, Mr Miliband joked on BBC Two's Victoria Derbyshire show: "It is true, I helped Theresa May write the speech."
He went on: "Let me give her a bit of credit for a second because I think what she did recognise in her conference speech and before was that this referendum, this Brexit vote wasn't just about Europe.
"Of course it was about Europe and immigration and so on but it was about a deeper dissatisfaction with the direction of the country.
"The question for her is can she deliver? Can she deliver on all the things she said?
"She's planning to cut tax credits which is going to be bad for the people she's talking about, I think hard Brexit will be bad for the people she's talking about.
"She was famously recently having dinner with Rupert Murdoch, I don't think he quite agrees with the strategy she's talking about.
"Where's the policy on non-doms, which was something I said, people who don't pay taxes, the richest in our society?
"I'll judge her on her actions."