Labour said its manifesto would bring about "real change" to overhaul Britain's "rigged" society as it pledged to boost wages, tackle climate change and re-nationalise key utilities.
Leader Jeremy Corbyn will reveal the full details of his election manifesto in Birmingham on Thursday, which is set to include promises of free broadband for all homes and businesses by 2030, more money for the health service and a fresh Brexit referendum.
Mr Corbyn called the fresh plans a "manifesto of hope" that were "fully costed", involving no tax increases for 95 per cent of taxpayers.
He issued a warning to supporters that his vision for government would be met with opposition in the remaining three weeks leading up to the December 12 polling day.
"Over the next three weeks, the most powerful people in Britain and their supporters are going to tell you that everything in this manifesto is impossible," said Mr Corbyn.
"That it's too much for you. Because they don't want real change. Why would they? The system is working just fine for them. It's rigged in their favour."
On Brexit, the party will keep to the position decided at its autumn conference of renegotiating an exit deal with the European Union by March and then putting those terms to a public vote within another three months, with Remain as an option.
The manifesto will contain intentions to significantly boost NHS spending, create a £10 minimum hourly wage for all, and tackle climate change by creating jobs in a "green industrial revolution".
A spree of social house building - the largest since the 1960s - will also feature, with a £75 billion plan, paid for through borrowing, to construct 150,000 homes a year.
The Labour leadership will be hoping the plans can turn around their fortunes in the polls.
The latest Telegraph/Savanta ComRes poll gives the Conservatives a double-figure lead of 11 points over Labour - the largest Tory lead seen by the poling company since before the 2017 snap election.
The results of the research, completed before Tuesday's head-to-head leaders debate between Boris Johnson and Mr Corbyn, has the Conservatives on 42 per cent and Labour lagging behind on 31 per cent.
The polling boost comes as the Tories look to drip-feed policy announcements in the run-up to the party's own manifesto launch next week.
Mr Johnson made a tax cut promise while on the campaign trail on Wednesday, vowing to lift 2 million low-paid workers out of making National Insurance contributions altogether by raising the threshold from £8,628 per year to £9,500.
Labour criticised the headline-grabbing move, estimating it would save low earners only £1.64 per week.
Housing Secretary Robert Jenrick will on Thursday divulge plans to build one million extra homes over the next five years.
He will also outline measures to make it easier for renters to buy, while providing more security for the 4.5 million people in the private rented market.
The announcements included providing more long-term fixed-rate mortgages that require only 5 per cent deposits, selling new-build homes to first-time buyers at a 30 per cent discount and banning no-fault rental evictions, while allowing tenants to "passport" their deposits from one property to another.
Meanwhile, Home Secretary Priti Patel is set to announce plans for the Tories to consult on doubling the jail sentence for those found guilty of attacking police and other emergency service workers, extending their time behind bars from one year to two.
The party was dogged by further controversy on Wednesday, however, after it barred The Daily Mirror from boarding its election bus in Manchester.
The left-leaning newspaper said it was the first time since the creation of touring election battle buses in the 1970s that it had been denied access to a Tory leader on the campaign trail.
Ian Murray, executive director at the Society of Editors, said the Mirror's exclusion was a "disturbing development" and "not acceptable nor compatible with the principle of media freedom".
The decision follows stinging criticism of the Conservative Campaign Headquarters' (CCHQ) for re-branding its Twitter account to look like a fact-checking operation during the leadership debate on ITV.
The Greens and the Liberal Democrats have already publicised their plans for government this week, with Lib Dem leader Jo Swinson declaring that her pro-EU party was not a "one-trick pony" after announcing a wide-range of incentives, including plans to provide childcare for all pre-school children over the age of nine months.
But, in what appeared to be an acknowledgement of the squeeze the Lib Dems have experienced in the polls, Ms Swinson acknowledged it would be a "big step" for her to get to Number 10 following months of insisting she was a credible contender for prime minister.
Sir Ed Davey, the party's Treasury spokesman, went so far as to open the door to supporting a minority Tory administration.
He told the BBC's Andrew Neil programme that the Lib Dems could strike a deal if Mr Johnson signed-up to holding a new referendum on Europe.
The senior figure said: "We will challenge him and we will work with others to say 'if you want to do what you said, Mr Johnson (to deliver Brexit)... if you want to do what you said, work for a 'people's vote'."