Jeremy Corbyn says the Tories are “starving” the NHS and schools of the resources they need.
The Labour leader promised to rebuild public services by investing billions in the NHS and social care.
The Conservatives responded by saying Mr Corbyn would fail to get a good Brexit deal for the UK, threatening investment in services.
They said a Tory government would increase investment in schools and the health system.
With polling day just over a week away, the two largest parties are focusing on their core messages – public services for Labour and Brexit for the Tories.
Mr Corbyn was joined at a speech in Westminster by his shadow health secretary Jon Ashworth and shadow education secretary Angela Rayner.
The Labour leader said: “Another five years of the Conservatives would be disastrous for our public services.”
He claimed that by 2022, 5.5 million people could be on NHS waiting lists in England.
On education, he said children were being crammed into classrooms with “begging letters” sent to parents asking for cash.
Mr Corbyn highlighted Labour’s plans to cap school class sizes at 30 for five to seven-year-olds and provide free school meals to all primary school children.
Labour has said it will invest £37bn in the NHS and £8bn in social care by the end of the next parliament if it wins the election.
The Conservatives are offering increases in NHS spending in real terms to reach £8bn extra per year by 2022/23.
Alongside that, they are proposing to change the social care system so that those receiving care at home are liable for costs if they have assets worth at least £100,000 – with a consultation taking place on a limit to how much people would pay.
They have said they will scrap free school lunches for infants in England, but offer free breakfasts across the primary years and pump an extra £4bn into schools by 2022.
Work and Pensions Secretary Damian Green said: “Made-up numbers from Corbyn cannot hide the fact he’s not up to the job of getting the deal we need.
“Theresa May has the plan to get the right Brexit deal, keep our economy strong, and invest billions more in public services. But a loss of just six seats and Theresa May’s government will lose its majority.”
The Liberal Democrats called for a cross-party commission to manage NHS funding in the long term.
The party’s health spokesman Norman Lamb said a long-term solution was needed, accusing the Tories of a “back of the fag packet” approach.
“I want an NHS that meets people’s needs but there’s a cost to that and we have to be honest with people,” he said.
Taking questions after his speech, Mr Corbyn brushed off reports about leaked proposals to allow unskilled migration from outside the EU as part of migration reforms.
“What you’ve been reading is a document that was being discussed between researchers in our teams, as happens every day of the week in every party all around Parliament,” he said.
“Our policy is in our manifesto.”
This would provide for “managed migration”, he said, which would be “based on the needs of our economy and the rights of family reunion”.
A seven-way general election TV debate takes place later, with Home Secretary Amber Rudd representing the Tories instead of Prime Minister Theresa May, who has refused to take part.
Mr Corbyn did not answer when asked whether he would be taking part, instead challenging Mrs May: “Come on prime minister, come and have a chat.”
Also on the TV panel will be Liberal Democrat leader Tim Farron, UKIP leader Paul Nuttall, SNP deputy leader Angus Robertson, Green Party co-leader Caroline Lucas and Plaid Cymru leader Leanne Wood.
It will be on BBC1 at 19:30 BST.