Jeremy Corbyn has said that Britain should not be afraid of debt or borrowing at the Welsh Labour party conference.
Addressing the conference at Llandudno, the Labour leader urged the Conservatives to "stop dithering" and start investing in Britain.
He said that Prime Minister Theresa May should take inspiration from the Atlee government when it came to spending power.
"We should not be afraid of debt or borrowing," said Corbyn.
"At the end of the Second World War, the Labour government of Clement Attlee didn't say, 'oh dear, debt is 250% of GDP, let's park those grand ideas about public ownership, a national health service, building council homes, or creating the protection of social security'.
"No, they built a country to be proud of. They established the institutions that made out country fairer, more equal and stopped people being held back because of the poverty of where they were born."
The leader also said that Labour would build homes, make the statutory minimum wage £10 an hour by 2020, and repeal the Conservative government's controversial 2016 Trade Union Act.
Responding to May's jibes that he wanted to bankrupt Britain, the opposition leader said that "united we stand divided we fall" and dubbed the prime minister "Theresa Hammond".
"Last week the prime minister twice accused me of wanting to bankrupt Britain by borrowing money to fund investment.
"But as every businessperson knows, there is a world of difference between borrowing for capital spending and borrowing to fund the payroll and day-to-day trading or service delivery.
"It's quite simple – united we stand divided we fall," he added.
"And united I believe this great party can do things together to achieve for the people that need Labour councils and, above all, need a Labour government and a society based on social justice and equality, not greed and inequality."
The Welsh Labour party is the most popular political faction in modern Welsh politics.
First Minister of Wales, and leader of Welsh Labour, Carwyn Jones, also announced that an extra £20m ($24.94m) would be provided for social care "to ease the burden on the NHS" at the conference.