Today's strike comes a day after a second legal challenge was launched against the government over its decision to impose the new contract.

NHS staff campaign group Just Health started proceedings after raising £100,000 in four days online.

The move followed separate legal action made by the British Medical Association last week seeking a judicial review.

A Department of Health spokesman said legal action was "expensive" for all parties and "totally unwarranted".

Read more about the legal action here.

Striking junior doctors have been finding lots of ways to keep busy on picket lines outside hospitals around England.

One of the biggest hospitals in Greater Manchester says it has now scaled down a major incident plan.

Planned operations were postponed at Wythenshawe Hospital and patients were urged to only attend A&E in a genuine emergency.

The move came after increasing demand on its A&E unit and a shortage of beds.  

University Hospital of South Manchester NHS Foundation Trust, which runs the hospital, said it was busy but "back to business as usual".  

Full story here.

Five members of the cast of Channel 4 sitcom Green Wing have been at the north London hospital where they filmed the series to lend their support to striking junior doctors.

Protesters have staged a "die in" outside the Department of Health, as they deliver a petition an online petition of some 120,000 signatures gathered on the Care 2 Community, external website.

Health Secretary Jeremy Hunt hasn't appeared for interviews this morning.

Reporter Charlotte Wright, who works for radio station LBC, was waiting outside his house earlier - but he didn't stop to chat.

There are more than 50,000 junior doctors in England. The term covers those who are fresh out of medical school through to others who have a decade of experience behind them.

So what responsibilities do they have? The BBC has spoken to three doctors at different stages of their career.

The Patients Association has backed the junior doctors' strike, saying it has watched the dispute with the government with "growing concern".

Katherine Murphy, chief executive of the Patients Association, said the imposition of the contract was not helpful to finding a resolution, and she was glad it was being challenged.

There have been reports that some junior doctors are considering quitting their jobs in the UK for work overseas if new contracts come into force.

The General Medical Council says so far this year, it has issued more than 2,200 "certificates of current professional status" which doctors need in order to work abroad, although not all who request them actually leave.

Dr Jason Seebaluk, 27, works in Euston, London. He says he is moving to Australia permanently in August because of the government's proposed amendments to junior doctors' contracts.

"I do feel a sense of guilt leaving but I have to think about my future," he says.

BBC News has been speaking to Dr Seebaluk and other junior doctors who are considering their futures.

Read the full article here.

Among the issues being highlighted by those on the picket lines are concerns that the new junior doctors' contract will hit female doctors harder than their male colleagues.

Analysis published by the Department of Health last week stated:

BBC News Channel

Ipswich Hospital says disruption has been minimal with about 160 outpatient appointments postponed. 

But chief executive Nick Hulme told the BBC the next planned strike at the end of April, which will include not providing emergency care, would be "a game changer".

He added that while everyone "had a right to strike", he felt many junior doctors had felt under pressure from the BMA to walk out.

Now the new contract had been published in full, he hoped more junior doctors would look at the detail and be willing to accept it.

A poll by YouGov, external released on Monday suggests that while the British public have been more supportive of the junior doctors' strikes than of industrial action in other industries, their support drops when it comes to action that extends to emergency care - as the next round of planned strikes on 26 and 27 April will.

The poll showed 59% support partial strikes, while 23% oppose, but support for full strike action falls to 44% and opposition rises to 37%.

Image source, Yougov

Victoria Derbyshire

The dispute now seems to have reached a real impasse - and the next planned strike really takes it into new territory by extending to A&E and emergency services. That's something that's never happened before. While it doesn't mean those services will stop - the health service will bring in extra staff - there will undoubtedly be a knock-on effect, particularly for planned procedures. 

We seem to have reached a point where two sides can't even agree on what they disagree on, and a complete breakdown of trust. Some doctors and patient groups have called on both sides to step back from the brink - for example, the Academy of Medical Royal Colleges is calling on the BMA to call off the strike and the government to call off the imposition of the new contract.

Public opinion has so far been fairly firmly behind junior doctors, but will that remain the case as there is further disruption? There is also the attitude of junior doctors who've walked out four times now. Will they continue to support strike action as it escalates, or will some of them decide that the battle has been going on for too long? That is certainly what the government would like to see.

Follow Adam at @adambrimelow, external

Image source, SPL

Responding to today's strike, NHS England says it has minimised the impact, but has "regret for the disruption patients will face and the fact that thousands of planned procedures will have to be rearranged, leaving people having to wait longer for treatment".

Dr Anne Rainsberry, national incident director for NHS England, said she expected the second day of the strike to be particularly difficult.

BMA representative Latifa Patel told BBC Breakfast the new contract would stretch staffing across NHS England too far.

NHS Employers has published the full details of the new junior doctors' contract, external, including a pay calculator for those affected.

Actor Stephen Mangan has been tweeting to say he and four other stars of the Channel 4 sitcom Green Wing will be visiting the hospital in north west London where they filmed the series to support doctors on strike there.

Our reporter Smitha Mundasad is with doctors on the picket line in Ipswich, and says there is no less passion than during the previous three strikes.

She's been talking to Dr David Rouse, from the British Medical Association, about the 24,500 delayed and cancelled treatments and operations that have resulted from the strikes - here's what he had to say:

Junior doctors across England have been tweeting images of the walkout.