The Labour leadership challenger Owen Smith has attacked what he said are "secret plans to privatise the NHS" within the Conservative party.
He said that the government had almost doubled the volume of private sector provision within the health service - and wants to go even further.
Speaking in Salford on Monday, Mr Smith said:
The MP for Pontypridd also criticised Prime Minister Theresa May's "error of judgment" in reinstating Jeremy Hunt as Health Secretary, whose handling of the junior doctors' contract dispute he described as being a "fiasco".
Mr Smith, who is taking on Jeremy Corbyn for leadership of the party, said that he would give the health service a 4% funding boost if Labour was elected to government.
It would be paid for by selling long-term gilts and raising an extra 13.5 billion pounds each year in taxes on the wealthy and major companies.
Mr Smith also denied that his bid to overthrow Mr Corbyn was creating a crisis within the party.
"I don't think we've been a powerful opposition, I don' t think we've held the Tories to account," he said.
He denied that he was pleased at a court ruling barring many new members from voting in the the contest, saying that he wanted it to be "as big and open" as possible.
"I have just got to play by the rules whatever they are," he added.