Jeremy Corbyn has promised to reverse the "turbo-Thatcherism" of former Conservative chancellor George Osborne by vowing to spend £500bn ($658bn, €591bn) of public cash on infrastructure, manufacturing and new industries across the UK.

The left-winger, who is facing Owen Smith in the Labour leadership contest, made the commitment during a rally in Dagenham, East London today (4 August).

"This government isn't the only one to blame, but it is the most gratuitous, with their failed austerity model of turbo-Thatcherism," Corbyn declared. "George Osborne cut government investment – the investment that provides a platform for people and businesses to thrive.

"The Tory government cut research spending by £1bn in real terms. How on earth are we going to become a strong modern economy if we cut science funding?

"They cut subsidies in renewables, the energy of the future. Germany and the US are pouring money into this. That's why we have announced a National Investment Bank to help channel £500bn of investment over the next decade."

But Corbyn, who failed to provide a costing for his previous commitment around equal pay enforcement, was vague on how a Labour government would fund his big 10 policies to "rebuild" Britain. The veteran parliamentarian told journalists that he would pay for the commitments by "expanding the economy" and tackling tax evasion.

Smith, meanwhile, has promised a "British New Deal" based off a £200bn fund. But Corbyn, who won almost 60% of the vote in Labour's 2015 leadership election, is expected to beat his sole rival in the contest.

A recent poll from YouGov for The Times, of more than 1,000 Labour members between 15 and 18 July, put him on 56%, with Smith on 34% based off first preference votes.

The pair will debate live on ITV Wales on Thursday night from 7pm BST in front of an audience of Labour members in Cardiff. The event will be the first hustings of the Labour leadership election campaign.