Average earnings are set to be £858 a year lower than previously thought by 2022 as workers "bear the brunt" of the Government's economic mismanagement, Jeremy Corbyn is warning.
According to Labour analysis of official forecasts, the average worker is set to be £2,257 worse off by 2022 as a result of slower earnings growth.
The Labour leader will use a speech to party activists to claim Philip Hammond's Budget was an "alarming expose" of Tory failure.
-- Jeremy Corbyn (@jeremycorbyn) November 22, 2017
The Office for Budget Responsibility (OBR) downgraded forecasts for growth in average earnings every year from 2017-18 to 2021-22 in its analysis published as Mr Hammond delivered his tax and spending plans.
Labour's analysis compared the forecasts from March with the updated version published on Wednesday and found that average earnings in 2021-22 are now expected to be £30,004 rather than the £30,862 implied by the earlier figures.
Across the five-year period, the cumulative effect of the lower forecast earnings amounts to £2,257.
Mr Corbyn will tell Labour supporters in Plymouth the figures mean that in 2021-22 "for the last three weeks of that financial year, everybody on the National Living Wage in Britain will effectively be working for free as they are denied the earnings previously expected".
"As the OBR says, it is workers who have to bear the brunt of the Government's poor management of the economy.
-- OBR (@OBR_UK) November 22, 2017
"Despite all the evidence, the Tories refuse to accept that cutting public services, holding wages down and refusing to invest is a recipe for failure.
"The Government cannot continue to tinker at the edges of an economy that is so completely broken. Our country needs a new and very different approach."
Mr Corbyn will use the speech to restate Labour's plans to scrap the public sector pay cap, pause the roll-out of universal credit and introduce a "real living wage" of at least £10 an hour by 2020.
He will also set out Labour's approach to the environment - highlighting the impact of the BBC's Blue Planet II programme in raising awareness of the seas and oceans.
In a signal that Labour will push for reform of fisheries policy after Brexit Mr Corbyn will say: "The EU's Common Fisheries Policy was not always helpful to the South West's fishermen.
"As we leave the EU, we must have a fisheries policy that supports the industry, creates good quality jobs, supports exports and enhances our environment."
-- The Labour Party (@UKLabour) November 24, 2017
A lack of new support for renewable energy projects until at least 2025 is "straight out of the Donald Trump environmental playbook", he will say.
He will call for the entire body of EU green laws to be transferred on to the UK statute book after Brexit adding: "Blue Planet II has shown just how important, beautiful and fragile our marine environment is.
"We will manage them with you, for you, and we will guard them for our future generations, too.
"This isn't some utopian pipedream but absolutely necessary if we are to preserve our planet for our children and grandchildren."