Junior doctors in England are set to begin a six-day walkout, the longest strike in the state-run National Health Service's 75-year history.

Junior doctors, represented by the British Medical Association, have staged a series of walkouts in demand of better pay in the face of soaring inflation and will begin their latest action on Wednesday.

The association recently abandoned talks with the government after being offered a pay rise of up to 10 per cent.

The union is seeking a 35 per cent improvement which it says is needed to cover the impact of inflation over several years.

The government, which has agreed new pay deals with other healthcare workers, including nurses and senior doctors in recent months, has resisted hikes it says would worsen inflation.

The strikes threaten to increase the pressure on the health service where over 7.7 million patients are on waiting lists for procedures and appointments.

"This January could be one of the most difficult starts to the year the NHS has ever faced," National Medical Director Stephen Powis said in a statement.

"The action will not only have an enormous impact on planned care, but comes on top of a host of seasonal pressures such as COVID, flu, and staff absences due to sickness."

Junior doctors are qualified physicians, often with several years of experience, who work under the guidance of senior doctors and represent a large part of the country's medical community.

A spokesman for Prime Minister Rishi Sunak said deals with other healthcare workers showed that the striking junior doctors were "outliers".

"We have sought to come to a fair resolution - fair for the taxpayer, fair for hardworking doctors and health workers," he told reporters.

"We have achieved that in the majority of cases ... we are willing to have further discussions. But obviously the first thing to do is to stop striking."

The BMA said a record waiting list and underinvestment over the past decade had undermined the NHS.

"As a profession we are exhausted, disenchanted, and questioning whether we want to stay in the health service at all," the union said.

"Add to this years of pay erosion, and it's no wonder that morale on the frontline has never been lower."