U.K. Prime Minister David Cameron pledged that his Conservative Party would boost annual healthcare spending by at least 8 billion pounds ($11.7 billion) by 2020 if re-elected next month.

The commitment forms part of a “landmark” five-year plan for the National Health Service, the government said in a statement Friday, and will help meet a 30 billion-pound funding gap identified by NHS England’s Chief Executive Officer, Simon Stevens.

“I believe in the NHS,” Cameron said in a personal message on his Twitter account. “It was there for me when my son needed help. A stronger economy allows us to fund it so it’s always there for you.”

The prime minister is targeting Britain’s healthcare system as he and opposition Labour Party leader Ed Miliband seek ways to win over voters before a general election in May that could be the closest in decades. A YouGov/Sun poll on Friday showed Labour ahead by 2 percentage points.

The majority of the NHS funding gap, or 22 billion pounds, is expected to be made through “efficiency and reform” as well as improvement in public health and prevention, wrote Chancellor of the Exchequer George Osborne in The Guardian newspaper. The commitment comes on top of the 2 billion pounds announced in the Autumn Statement.

“The NHS is something precious,” Osborne wrote. “We will always give it the resources that it needs.”

Other changes to be announced include giving people over 75 the right to “same-day access” to see a doctor and better weekend access to physicians by 2020, helping to reduce the number of unnecessary visits made to hospitals, he said.

Health Secretary Jeremy Hunt told The Daily Telegraph that the extra funding will pay for at least 5,000 new general practitioners.