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David Cameron has urged junior doctors to call off their planned strike.

He warned Tuesday's strike will cause "real difficulties for patients and potentially worse".

The strike begins across England at 08:00 GMT, from when junior doctors will only provide emergency care.

Talks between the doctors' union - the BMA - and NHS bosses continue. The BMA has said the strikes "demonstrated the strength of feeling amongst the profession".

Issues being disputed by the BMA and NHS include weekend pay and whether there are appropriate safeguards in place to stop hospitals over-working doctors.

Three strikes are set to take place from:

08:00 Tuesday 12 January to 08:00 Wednesday 13 January (emergency care will be staffed)

08:00 Tuesday 26 January to 08:00 Thursday 28 January (emergency care will be staffed)

08:00 to 17:00 Wednesday 10 February (full walk-out)

The Prime Minister called on medics "at the late stage" to get back around the table before the proposed walkout.

He said: "This strike is not necessary, it will be damaging.

"We are doing everything we can to mitigate its effects but you can't have a strike on this scale in our NHS without there being some real difficulties for patients and potentially worse."

NHS England estimates nearly 4,000 operations and procedures out of 31,000 will be cancelled because of the strike.

It says everything possible is being done to provide safe emergency care and minimise the impact on patients.

Anne Rainsberry, the NHS England director overseeing preparations, said: "We have tried and tested plans to deal with a range of disruptions including industrial action. As ever, the safety and care of patients is our top priority and the NHS has robust plans in place to ensure those who need emergency treatment will continue to receive it.

"We have been working with hospitals and other NHS providers across the country to ensure we can continue to protect the safety of our patients and provide the urgent services they need. We will monitor the situation across the country to ensure these plans are in place, and are ready to respond to any significant increases in pressure in any region over the course of this dispute."

What is the dispute about?

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The row between junior doctors and the government is over a new contract

Talks broke down in 2014, but the dispute has escalated since the summer after ministers said they would impose the deal

Ministers offered doctors an 11% rise in basic pay last year, but that was offset by curbs to other elements of the pay package, including unsociable hours payments

The government has said the changes are needed to create more seven-days services, but the BMA has warned it could lead to doctors being over-worked because safeguards to keep a lid on excessive hours are being weakened

The union balloted its members in the autumn and 98% who voted backed strike action

Talks re-started in December, leading to the planned three days of strikes being cancelled, but these have so far failed to reach a breakthrough which is why strikes are taking place

The junior doctors row explained

What patients need to know

What exactly do junior doctors do?

How does your job compare?

The lessons of the 1975 doctors' strike

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