This country faces massive strikes by doctors

Junior doctors in the U.K. are set to strike next month, in the first full walkout in the history of the National Health Service (NHS) that could see thousands of operations and appointments delayed or canceled.

Here's what you should know:

Doctors in the U.K. are largely employed by the NHS, which provides free healthcare to all U.K. residents. This means their salaries and contracts are set by central government.

The planned strikes, set for three dates in December, are in response to contract changes proposed by Health Secretary Jeremy Hunt from the ruling Conservative Party. The proposals, published on November 4, aim to cut back on the hours for which junior doctors — those below consultant level — can receive a premium pay rate.

This is part of a plan to build an affordable seven-day-week NHS, in which non-emergency health services are available across the weekend and outside office hours.

At present, junior doctors receive a higher pay rate for shifts worked any time on the weekend and between 7 p.m. and 7 a.m. on weekdays. Under Hunt's plan, this higher pay rate would only apply between 10 p.m. and 7 a.m. on weekdays and after 7 p.m. on Saturdays.

Hunt plans to increase junior doctors' basic pay by 11 percent to compensate them — but they say this is insufficient and would result in lower overall earnings.

Currently, the basic salary for a first-year graduate doctor in the U.K. is £22,636 ($34,514), rising to £28,076 ($42,809) in their second year, according to government data.

A social media campaign by junior doctors has become increasingly vitriolic in recent months about Hunt's plans.

The British Medical Association (BMA) — the trade union representing doctors and medical students in the U.K. — balloted members on Thursday on whether to strike. 98 percent voted in favor of striking, with voter turnout at 76 percent.

"We want a safe and fair contract for junior doctors. To do this we need to robustly resist an imposition of a contract that is unsafe for patients, and unsafe and unfair for doctors," the trade union said on its website.

Under the strike plans, junior doctors will provide "emergency care only" on December 1, followed by a full walkout on December 8 and December 16.

This is the first time in NHS history that junior doctors will provide no care whatsoever as part of strike action. It is expected that consultants will be drafted in to cover emergency care, however, thousands of scheduled operations will be delayed and outpatient appointments' canceled.

Hunt said on Thursday that striking would put patients at risk.

"It is regrettable that junior doctors have voted for industrial action which will put patients at risk and see operations canceled or delayed. We want to ensure patients have the same quality of care across the week and have put forward a generous offer that increases basic pay by 11 percent and reduces doctors' hours," he said in a statement on the U.K. governmental website.

"We hope junior doctors will consider the impact this action — especially the withdrawal of emergency care — will have on patients and reconsider."

The BMA's last dispute with the government was in 2012, over doctors' NHS pensions.

U.K. junior doctors last went on strike as a group in 1975, in relation to the non-payment of work done outside their standard 40-hour week — at the time, some doctors worked 100-hour weeks. The strike action involved the doctors working their 40-hour week, but refusing to do more.

A new contract was agreed by doctors and the government in early 1976.

One concern about doctors striking is that it may set a precedent, emboldening future generations of doctors to do so.

In some developed countries, strikes by physicians are comparatively common. In New Zealand — a country with a broadly similar health care system to the U.K. — doctors striked in 1992, 2006 and 2008, for instance.

Doctors' strikes are rare in the U.S., but physicians working in student health centers staged a one-day strike in January at 10 University of California campuses. They said that administrators had failed to give their union information needed for contract negotiation.

Another notable bout of industrial action took place in Israel in 1983, when 3,000 doctors went on a hunger strike. This lasted for two weeks and received heavy media coverage before the government agreed to arbitration.

Doctors' basic starting salary is unimpressive compared with what is on offer from the leading employers in the U.K. Graduate starting salaries at public, private and non-governmental organizations featured in The Times Top 100 Graduate Employers reached a median of £30,000 in 2015, according to High Fliers, a recruitment research company.

Graduate salaries in the public sector — including health, transport, teaching, international development, the armed forces, police, civil and security services — tell a different story, with a median starting salary of only £20,000.

At present, the starting salaries of junior doctors in the U.K. slightly lag those in comparable health systems, particular once costs of living are factored in.

In New Zealand, doctors in urban areas earn 52,843 New Zealand dollars ($34,662) on graduation and 54,957 New Zealand dollars ($36,049) elsewhere.

In Australia, a first-year medical graduate or "intern" earns a basic salary of around 63,099 Australian dollars ($45,608).

— By CNBC's Katy Barnato. Follow her on Twitter @KatyBarnato.