Jeremy Corbyn will on Wednesday attack the “greed-is-good” capitalism that he claims has resulted in large swaths of the UK being left behind, promising a raft of new policies including a “green jobs revolution” that will create 400,000 new positions.

The Labour leader will attempt to reset the theme of the Labour conference which has so far been dominated by deep divisions over its Brexit stance and return to his core argument about the failure of the broken economic system.

Corbyn will use his main conference speech to set out his plans to change the direction of the economy, following a week in which his shadow chancellor, John McDonnell, laid out a series of redistributive policies.

The Labour leader will say: “Ten years ago this month, the whole edifice of greed-is-good, deregulated financial capitalism, lauded for a generation as the only way to run a modern economy, came crashing to earth, with devastating consequences.”

”But instead of making essential changes to a broken economic system, the political and corporate establishment strained every sinew to bail out and prop up the system that led to the crash in the first place.

“People in this country know – they showed that in June last year - that the old way of running things isn’t working any more. That’s why Labour is offering a radical plan to rebuild and transform Britain.”

Corbyn will announce plans for a rollout of green technologies including 13,500 onshore and offshore wind turbines, solar panels on thousands of roofs and wide-scale home insulation.

A green energy report published by the party on Wednesday will hint at an expansion of other renewable technologies to come, including tidal power, hydrogen and controversially, nuclear, which would help meet tough climate change targets.

He is expected to say: “There is no bigger threat facing humanity than climate change. We must lead by example. Our energy plans would make Britain the only developed country outside Scandinavia to be on track to meet our climate change obligations.

“Our programme of investment and transformation to achieve a 60% reduction in emissions by 2030 will create over 400,000 skilled jobs, based here and on union rates, bringing skills and security to communities held back for too long.”

The move is designed to be a big offer from the party to help regenerate so-called left behind towns. Many of them are traditionally Labour but leave-backing seats where the party went backwards in support at the last general election.

Corbyn is expected to tell party activists that the programme would bring “skills and security to communities held back for too long”. Labour wants 60% of heat and electricity to come from low-carbon or renewable sources by 2030.

Following a fraught summer dominated by rows over antisemitism, a Labour spokesman played down expectations that Corbyn would apologise directly to the Jewish community in his speech, suggesting that he had already done so.

Corbyn will instead concentrate on his plans to reform capitalism, which have so far been fronted by McDonnell, and include policies to tackle high pay and excessive corporate bonuses.

However, Labour aides did not expand on how Corbyn would have dealt with the financial crisis differently, insisting that he believed the last Labour government had done all that it could, and that it was the system that had been at fault.

The promised investment in green technologies would be paid for from Labour’s £250bn national transformation fund, announced at the last general election, with the home insulation programme alone costing £12.8bn through a variety of subsidies.

The plans would involve a dramatic sevenfold increase in offshore windfarms by 2030, with 7,500 turbines powering 12m homes and creating 120,000 jobs, including in the north-east and Humber.

There would be 6,000 more turbines onshore, powering 5m homes and creating 60,000 jobs, an ambitious target given the scale of opposition to many existing windfarms.

Labour would also invest in solar panels, reversing Tory cuts to power 2.5m homes and create 70,000 jobs. It would insulate homes to high energy efficient standards, creating a 160,000 army of energy assessors, engineers, technicians.

The party has already committed to reducing greenhouse gas emissions by 60% by 2030 and to zero by the middle of the century.

The announcement is reminiscent of a pledge from Gordon Brown in 2009 for a “green revolution” which the then prime minister said would create 400,000 jobs over eight years.

Among the other policy announcements in the speech are details of a plan to extend the government’s 30 hours of free childcare scheme to the parents of all two-, three- and four-year-olds, which would benefit more than a million children.

Families on the lowest incomes would be eligible for additional subsidised hours on top of the 30 hours, which would be free for them and cost no more than £4 per hour for those on the highest incomes, with a sliding scale in between.

Corbyn will also pledge to increase average early years funding rates to help the many childcare providers that are struggling – some have even closed – as a result of the 30-hour policy, which they argue is not properly funded.

The childcare system would be simplified for parents with the launch of a national childcare online access portal, which would replace the existing complicated mix of vouchers and credits.