Schools, hospitals and other public services left "devastated" by "ideological" Conservative cuts face a fresh squeeze on finances, Jeremy Corbyn has claimed.
In the final hours of campaigning before the polls open on so-called "Super Thursday", the Labour leader said the Tories needed to find billions to fill a budget black hole and could "no longer be trusted" to protect communities.
Voters will have their first chance to deliver a verdict on the Opposition leader since he took control last September, in a win that sent shockwaves through the party.
Mr Corbyn has insisted he will face down any challenge to his leadership and raised eyebrows when he made the bold claim that Labour was "not going to lose seats" on Thursday.
The party leader is urging voters to send the Tories a message when they head to the ballot box, warning that the Government needs to find ways to fill a gap of £4.8 billion in funding in 2019 left by the U-turn on personal independence payments and other planned cuts that are yet to be specified.
The shortfall is equivalent to the loss of 2,900 police officers, nearly 20,000 nurses and 18,000 midwives and 16,500 teachers as well as 3,000 residential social care places for the elderly, according to party analysis.
Labour has called an Opposition Day debate in the Commons to raise plans to scrap NHS bursaries for student nurses, midwives and other health professionals.
Mr Corbyn said: "The Tories have made it clear they don't stand up for people's priorities. Their ideological cuts have devastated public services, leaving the NHS with the worst A&E waiting times since records began, and an unnecessary dispute with junior doctors.
"Rather than tackle rising class sizes in schools or the shortage of teachers, they are now preparing to spend over £1 billion on a top-down reorganisation of schools than nobody wants.
"The systematic dismantling of our public services has meant 4,500 fewer firefighters, 18,000 fewer police and a care system unable to give the support that elderly and disabled people need.
"The Tories' failed economic policies mean there is now a multi-billion black hole to fill in this Parliament. The Tories can no longer be trusted with our communities so send them a message on 5 May, vote Labour."
Polls open on Thursday for Scottish Parliament, Welsh Assembly and Northern Ireland Assembly elections as well as for 124 councils in England and the Greater London Assembly.
Voters will also choose mayors in London, Bristol, Liverpool and Salford, and police and crime commissioners in most areas in England.
London mayoral candidate Zac Goldsmith will campaign through the night, dropping in on some of the capital's night workers at food markets, a supermarket delivery hub and a railway depot.
Mr Goldsmith admitted his battle against Labour's Sadiq Khan would "go right down to the wire".
He said: "Hundreds of thousands of people work tirelessly to make our City great, and that's exactly what I'll do as mayor.
"My action plan for Greater London will keep the economy strong, keep London moving, ensure our streets are kept safe and make London the greenest and cleanest city in the world.
"I'll help out Londoners by freezing mayoral council tax, and I'll get the Tube working through the night so it's easier to move around. This campaign is the fight of my life, and it will go right down to the wire on Thursday."
David Cameron insisted the Conservative MP would protect family finances.
"Only Zac can secure the success we've seen under Boris over the last eight years," the Prime Minister said:
"This election really matters - it's a clear choice and it's in your hands. If Zac wins, London wins."