Junior doctors are preparing to strike every month until next spring, medics have said.
The British Medical Association (BMA) said it will ballot training doctors next week to extend its strike mandate.
Junior doctors said they will also consider “co-ordinated action” with consultants, who are also currently being balloted over the possibility of strike action.
If members vote to continue strikes, junior doctors will take to picket lines for three days a month, every month, until March 2024, the PA news agency has learned.
The move would represent a significant escalation in the dispute with the Government over pay.
Junior doctors across England are currently on strike for 72 hours.
It is the third round of strikes by training medics in the current dispute, with past walkouts taking place in March and April.
It comes as hundreds of junior doctors staged a rally outside the NHS ConfedExpo conference in Manchester, where Health Secretary Steve Barclay is set to speak later on Thursday.
Medics chanted: “What do we want? Fair pay. When do we want it? Now.”
Chants of “cuts don’t pay the bills” were also heard.
In an interview with PA, Dr Vivek Trivedi, co-chairman of the BMA Junior Doctors’ Committee, said: “We have said that we are prepared to take three days of action every month for the rest of our mandate if we need to – but that’s the key thing, if we need to – and we didn’t actually even need to take strike in the first place.
“We only took action because we were ignored by the Government.
“And even now, Mr Barclay – well, it actually seems to be Mr Sunak who is actually pulling the strings – has the ability to get these strikes called off.
“All we need to know is that he’s serious, he’s willing to put a credible offer on the table that we can use to negotiate with.
“And going forwards, if we’re happy to have an open, honest conversation, then we don’t need to ever go on strike again.
“But if the Government continue to act in bad faith, as they have repeatedly in the past, we are preparing for further strike action and actually are making preparations to re-ballot our members to extend our strike mandate.”
Dr Trivedi added: “Our mandate expires on August 19 and we will be re-balloting from June 19, which is next Monday up until the end of August.
“That will take us through to February/March 2024 and we would re-ballot at that point if we needed to.
“The key emphasis on ‘if we need to’, which we don’t if the Government meets us.”
Asked if junior doctors will consider striking alongside consultant colleagues, Dr Emma Runswick, deputy chairwoman of the BMA council, told PA: “Patient safety is top of our agenda so I can’t see a world where it would be simultaneous, but will it co-ordinated? The answer has to be yes.
“The question is, ‘How do we get the Government to shift their position?’ which is so unreasonable at the moment.
“And if it takes co-ordination of action to do that then that’s what we’ll do.”
Dr Runswick said co-ordinated action could include consecutive strikes from juniors and consultants, with junior doctors taking action before or after any potential consultant walkout.
She said: “There is remarkable understanding from patients and the public on picket lines that if we… if we don’t turn this trend around, waiting lists will only go up and people who are in hospital receiving urgent care will get worse care slower.
“So I think there is widespread understanding of the importance of this dispute.”
Many key NHS figures ducked out of the NHS’s annual meeting to manage the strike’s fallout.
NHS England boss Amanda Pritchard said the strike is a “serious risk to patient safety” and industrial action “creates risk and upheaval”.
She said tens of thousands of appointments will be affected.
Speaking before leaving the conference to co-ordinate the strike response from the London office, she told delegates on Wednesday: “We must prioritise the management of what is a serious business continuity incident and therefore a serious risk to patient safety.”
She added: “As much as we learn from managing each action every time it happens, it creates risk and upheaval and distracts from our priorities, particularly elective recovery.
“Over half a million appointments have already had to be rescheduled. Many of those people will have been waiting months.
“It’s likely we’ll see tens of thousands more affected this week.
“So while the NHS will of course expertly manage the incident to the best of our ability, I know we all hope for a resolution soon.”
Asked about Ms Pritchard’s comments, Dr Trivedi told PA: “I’m happy to have a chat with her and explore with those risks that she thinks that exist there.
“Looking at the evidence from the first and second round of strikes is that patient safety was maintained and wasn’t put at risk.
“So I don’t think there’s anything to suggest that, from the information that I’ve seen, that that has changed with our third round of action.”
