Labour will start nationalising water and energy companies within 100 days of taking office, John McDonnell will announce as the election campaign enters its final 72 hours.
The shadow chancellor is expected to use a speech in London on Monday to announce the move, which will include "governing boards" made up of workers, politicians and customers.
These boards will have to broadcast their decisions live on social media, he will say.
Three days ahead of polling day, Mr McDonnell will also tell voters his first budget, to be held within weeks of Labour winning, will end austerity as its number one priority.
He will say Labour will get investment flowing to communities that have been "neglected for decades" as part of the party's "green industrial revolution".
And he will promise to "put British industry back on the map, bringing prosperity to every part of our country".
Conservatives target 'red wall'
While Mr McDonnell makes his announcement, Boris Johnson will be trying to crack the so-called "red wall" of Labour seats across the North of England to deliver a Conservative majority.
In the city of Sunderland - the first area to vote to leave the EU in 2016 - Mr Johnson will tell voters that Labour has "let you down most of all" on Brexit.
He will blast Labour for sticking "two fingers up to the public" for promising to honour the result then proposing another referendum during its current campaign.
Lib Dems soften 'stop Brexit' stance
On the Lib Dems campaign trail, leader Jo Swinson appeared to soften her party's Brexit stance.
She said the party has "ready to go" plans to trigger a new Brexit referendum, with two draft bills ready to be put before parliament as soon as they get into power.
She said one bill would enable the Electoral Commission to start a consultation about a referendum question and lead campaign designation, while the second would provide for an in/out referendum.
The party has, so far, been running on a staunch "stop Brexit" platform by promising to revoke Article 50, with the announcement marking a drift away from that.
It is more in line with a caveat in the Lib Dem manifesto which says: "In other circumstances, we will continue to fight for a people's vote with the option to stay in the EU."
SNP warning to Labour
SNP leader Nicola Sturgeon addressed a potential coalition with Labour, by warning senior Labour figures that rejecting negotiations with her party - including a second Scottish independence referendum - could risk putting Boris Johnson back in Downing Street if there was a hung parliament.
"I don't think they're going to turn their backs on that," she told the BBC's Andrew Marr Show
"If they do, I think they've got some big explaining to do."
Leading doctor and NHS official attack all parties' health plans
The Conservatives, Labour and Lib Dems were given grave warnings by two leading public health sector officials who said their promises are misleading or impossible.
Professor Andrew Goddard, president of the Royal College of Physicians, warned none of their NHS promises are "physically possible" as there is a lack of people in training to fulfil them.
The gastroenterologist said he was frustrated "by the proposed policies and promises" by Labour and the Conservatives, and their "relationship to reality and what actually is deliverable".
And he said patients in hospital should get used to seeing their doctors less because the health service will reach "crunch point".
Chris Hopson, chief executive of NHS Providers', the hospitals' membership group, said politicians had ducked the big issues in regards to health and social care.
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