David Cameron will guarantee every NHS patient access to a GP seven days a week by 2020 under plans to be unveiled at the Conservative Party conference.
The Prime Minister is expected to announce a £100m spending boost to improve access to family doctors should the Tories win next year's election.
The plans seek to ensure more people will be able to see their GP between 8am and 8pm on weekdays and weekends.
GPs will also take responsibility for individual patients as part of a new GP contract being launched by NHS Employers.
Mr Cameron is expected to say: "People need to be able to see their GP at a time that suits them and their family.
"That's why we will make sure everyone can see a GP seven days a week.
A £100m spending boost will be announced to improve access to GPs"We will also support thousands more GP practices to stay open longer, giving millions of patients better access to their doctor.
"This is only possible because we've taken difficult decisions to reduce inefficient and ineffective spending elsewhere as part of our long-term economic plan.
"You can't fund the NHS if you don't have a healthy, growing economy.
"This will help secure a better future for Britain, where people can be confident that when they or their loved ones need it, our NHS will be there for them."
:: David Cameron will talk to Sky News at 7.30am. Watch Sky News live on television, on Sky channel 501, Virgin Media channel 602, Freeview channel 132 and Freesat channel 202.
The announcement comes after Chancellor George Osborne claimed the Tories, not Labour, are "the real party of the NHS".
Last year Mr Cameron set up a Challenge Fund for GP access which allocated £50m to 20 health groups.
Under a second wave of proposed funding, practices will be able to bid for awards from the extra £100m fund.
Mr Cameron says people need access to GPs at times that suit themSky's Political Editor Faisal Islam said the NHS is set to be "front and centre" of the campaign leading up to next year's election.
"This is a new front, the NHS. They (the Conservatives) won't cede this ground to Labour," he said.
"They are convinced that if Labour is ahead on the NHS in polling and behind on the economy, they have to have a strong promise on the NHS.
"This is the beginning of what we will get and it's going to be a continuing battle."
But the commitment has already drawn criticism from Labour, which argues the government has made it "harder, not easier" for patients to get a GP appointment.
Shadow Health Secretary Andy Burnham said: "David Cameron made an almost identical announcement this time last year but, in the 12 months since, he has made it harder, not easier, to get a GP appointment.
"After the election, David Cameron scrapped Labour's GP appointment guarantee and cut support for evening and weekend opening. His broken promises on the NHS have caught up with him."
On Monday, Mr Osbourne announced a two-year freeze on benefits for those who could be working.
Mr Osborne said Britain can no longer afford to be a country where £100bn is spent on paying benefits for those of working age.
"Families out of work should not get more than the average family in work," he said.