Image source, Facebook

This screengrab of a Facebook posts, provided by a BBC News producer, appears to show a doctor at Sandwell Hospital in the West Midlands confirming there is a "level 4" incident, meaning the striking junior doctors have been asked to come back to work. 

Bosses at Sandwell Hospital in the West Midlands have asked junior doctors to come off the picket line because of a surge in activity and problems discharging patients.

It is not yet clear whether the junior doctors are complying with this request. 

Dr Inez Von Rege, who is on a picket line at St Thomas' Hospital opposite Parliament in London, says she never imagined she would ever be on strike. She also says the government's action on changing contracts was a step towards privatising the NHS. 

"They are completely demoralising doctors and believe they can turn the public against us - but we are receiving a lot of support for what we are doing. 

"My pay will be cut by 30% under the proposed contracts so what the government is saying is a complete lie."

Consultant Partha Kar has tweeted this image of junior doctors and other staff on emergency cover in Portsmouth.

Junior doctors in England plan to take industrial action later  in January - Tuesday 26 through to Thursday 28 - as well as on Wednesday 10 February.

Here's what you need to know if you're a patient due for treatment during either of those dates, or also today.    

NHS England says that everything possible is being done to ensure the provision of safe emergency care and to minimise the impact on patients.

But it expresses regret that thousands of planned procedures would have to be rearranged and that people would have to wait longer for treatment as a result.

These junior doctors are on a picket line at the Royal Devon and Exeter NHS Foundation Trust. 

Nadia Masood, 34, who organised the picket at Great Ormond Street, says she had been a junior doctor for 11 years and wanted to keep the NHS "safe". 

"We really want the government to finally realise and acknowledge and properly address just how serious our concerns are - 98% of junior doctors voted for strike action and this is the first strike in 40 years. 

"This isn't the first time we have been mistreated by the government though, that just tells you how bad these changes are. 

"We want them to promise us in writing, in public that they are actually going to address the concerns that we have. And so far, they haven't. They've given us pretend negotiations."

NHS doctor Aoife Abbey has tweeted this image of tea being handed out on her picket line - not quite clear where that is, however.

Dr Kitty Mohan, from the BMA's junior doctors committee, told the BBC's Radio 4 Today programme that government assurances "simply aren't good enough here". 

"We really need proper contractual safeguards in order to keep junior doctors - and their patients - safe." 

When asked if doctors are prepared to go through with all three planned strikes, she said: "It is exceedingly difficult for junior doctors. This isn't the reason why we go into medicine and have a medical career. 

"Even today is breaking the heart of many junior doctors and therefore we really urge the government to negotiate with the BMA." 

Image source, PA

The National Health Singers, external have gathered outside Great Ormond Street Hospital in London to lend its support to striking doctors, where they sang their current single "Yours".

Jeremy Corbyn has posted a message on Facebook, saying the government was to blame for the strike going ahead. He also called on ministers to apologise to junior doctors. 

Image source, Facebook

If you want to follow Twitter updates on today's strike, then the  #juniordoctorsstrike, external hashtag is currently the most popular on there. 

Image source, PA

So what is the row involving junior doctors all about? The BBC's health correspondent Nick Triggle has written an explainer, giving all the details on what's caused the dispute. 

Image source, Reuters

Liberal Democrat former deputy prime minister Nick Clegg tells the BBC Radio 4 Today programme that "something has gone wrong" between junior doctors and the government. 

He says: "No-one wants a strike and I understand the public concern about the effect of a strike, but equally my experience is that junior doctors, on the whole, are very hard-working men and women who also understand, as Jeremy Hunt has said, that people fall ill at weekends and need to be properly cared for."