Ed Miliband's pledging £2.5b in extra cash, paid for, in part, by taxes on expensive properties and a crackdown on tax avoidance.
"Privatisation cannot meet the needs of a 21st Century health service," said Mr Miliband.
Labour claims it would also restrict the profits private firms could earn from contracts to run services on the NHS.
"The money we pay for our health care should be invested for patient care and not for the excess profits of private firms," he added.
Speaking on Premier's News Hour, Susie Stride, a Christian, and Labour candidate for Harlow in Essex said the NHS was one of the main issues people she was meeting on the doorsteps was concerned about: "Having knocked on thousands of doors and spoke to many, many people, the top issue that people care about, not just in Harlow but across the country, at this time is the NHS.
"People are very, very worried that David Cameron voted for a Bill which effectively means that the NHS can be privatised and reorganised."
She told Premier's News Hour he's right to focus on the NHS.
Scottish Labour leader Jim Murphy's also launched his party's general election campaign, promising to help the poorest in Scotland.
He pledged to end the need for foodbanks and says he also wants to get rid of the so-called 'bedroom tax' as well as raising the minimum wage.
Mr Murphy has claimed it's not right so many families rely on charity to put food on the table: "Foodbanks are the biggest growth industry in our country. It's wrong that someone goes out to work, they set the alarm clock in the morning, they get their kids to school, they go to work and they take a break at lunchtime to go to a foodbank so they can feed their kids at home, when they get home after work."
Susie Stride, Labour candidate, Harlow: