Junior doctors have joined picket lines at hospitals in Suffolk and Essex as they begin the first all-out strike in the organisation’s history.

Hundreds of patients face cancelled operations or rescheduled appointments in the region today as the junior doctors’ strike steps up a gear.

The first all-out strike by junior doctors in the history of the NHS will affect 1,369 patients at the three main hospitals in Suffolk and north-east Essex after last-ditch efforts failed to break the stalemate over a new contract.

Here is a Q&A about the industrial action:

What is the dispute about?

The Government is intent on introducing a new contract for doctors working up to consultant level to replace one it says is outdated.

Health Secretary Jeremy Hunt wants to cut the number of hours over a weekend for which junior doctors can claim extra pay, while offsetting this with a hike in basic pay.

This has proved a major sticking point in the row with the British Medical Association (BMA) – whether Saturdays should attract extra “unsocial” payments.

Currently, 7pm to 7am Monday to Friday and the whole of Saturday and Sunday attract a premium rate of pay for junior doctors.

The imposed contract, due to come into force in August, has an increase in basic salary of 13.5% but 7am to 5pm on Saturdays will be regarded as a normal working day. There will still be premium rates for Saturday evenings and all of Sunday.

The BMA has rejected these plans.

Why is this strike worse?

NHS leaders are more worried about the latest strike because junior doctors are withdrawing full labour, including emergency care. This puts the NHS under increased pressure, although routine operations and appointments have been cancelled so staff can concentrate on patients in most need.

Wasn’t there something about death rates?

Yes. Jeremy Hunt angered junior doctors by repeated references to higher death rates for patients in NHS hospitals at weekends.

While the research does suggest thousands more people may die following admission at weekends than during the week, researchers have been very cautious about suggesting that staffing issues are to blame.

Doctors accuse Mr Hunt of conflating the arguments by saying that unless contracts are reformed immediately, patients will continue to die.

What happens now?

The BMA is launching a judicial review and other pressure groups have also launched legal challenges over the legitimacy of the contract.

There is a suggestion that doctors could walk out indefinitely if the Government imposes the contract.

What impact has the strike had on patients?

In total, 168 planned operations scheduled for today or tomorrow have been cancelled at Ipswich Hospital, West Suffolk Hospital (WSH) in Bury St Edmunds and Colchester General Hospital. Another 1,201 outpatient appointments have been rescheduled.

Last night, hospital chiefs warned that A&E wards must be used only for serious or life-threatening emergencies during the strike. But they said plans are in place to provide safe care and repeated advice for patients to call NHS 111 or visit pharmacies for alternative help and treatment.