A letter from Mark Easton, chief officer of the North-West London collaboration of CCGs (NWLCCCGs), says the group's eight CCGs had forecast a total £51m deficit at year end. But their current position suggests that 'we are at risk of an additional £61m overspend' - £112m in total.
A financial recovery plan being drafted by NWLCCCGs, will require 'some difficult choices', the letter warns, adding that 'some ideas, particularly those affecting patients, will generate strong views'.
Under the plan, GPs will be asked to refer more patients locally to reverse a 'large increase in the number of patients referred out of sector'. The CCGs aim to bring 15% of elective cases referred out of the area to local acute providers - with a view to saving '30% on tariff costs'.
GPs will also come under pressure to limit referrals - the letter says that CCGs within the NWLCCCGs area will 'profile acute contracts by primary care network (PCN) and practice, so GPs know how much activity is left on the acute contract and when it is being exceeded'.
The group also plans to 'significantly reduce consultant to consultant referrals, follow-ups and outpatient procedures'. The letter says patients are 'having to attend outpatients unnecessarily when there are better options' - and highlights that consultant to consultant referrals represent 20% of the total £250m spent on outpatient services each year across NWLCCCGs.
In addition to concerns about patient safety, the move threatens to drive up GP workload. GP leaders have long warned that hospitals waste millions of primary care appointments each year by dumping work on general practice - including by forcing patients to return to their GP practice for an onward referral to a new department within a hospital.
Londonwide LMCs chief executive Dr Michelle Drage said: 'Rationing care in this way harms patients by denying access to services they need. GPs do not refer patients on a whim, but on the basis of sound medical judgment and experience.
'There is a real risk that GPs and primary care staff will now be spending a lot more time on the phone to hospital administrators advocating on behalf of their patients, which is all time which could better be used for patient care.
'Once again it falls to frontline NHS workers to be the ones who have to tell patients that the government does not want to fund the service properly. Rationing is also financially counter-productive, we will see a fall in early interventions and more patients going on to develop complications to their conditions, which the NHS still has to treat and manage.'
A NWLCCCGs spokesperson said: 'No matter the financial challenges we face, as a clinically-led NHS body our priority will always be the safety of our patients and the quality of NHS services. We will start by removing waste and duplication from areas that will not affect patients.
'We have written to partners and stakeholders, including patient representatives to provide transparency about the areas we will be looking at. We will engage on any changes that directly impact patient care and will listen carefully as we shape our plans.'
The letter from Mr Easton lists factors that have contributed to the nine-figure predicted deficit across NWLCCCGs.
He says that expected population growth since 2015 has been 'outstripped by increased demand for hospital care', a lack of standardisation of clinical processes across the area has driven up costs, and a lack of capital funding to tackle long-standing estates problems, rising staff costs and low budget increases have contributed to the area's financial problems.
A NWLCCCGs spokesperson pointed out that consultant to consultant referrals were being targeted because they 'have increased much faster than GP referrals'. The spokesperson added: 'We think not all are appropriate, and some are miscoded and not true consultant to consultant referrals.
'We will not restrict referrals between specialties within agreed pathways, and nor will we do so in case where patients require an urgent opinion. However, we do need to work out why there has been such apparent unplanned growth, make sure the coding is correct and stop inappropriate referrals.'
On outpatient follow-ups, the spokesperson said that 'all outpatient specialties will continue to deliver follow-up care and procedures', adding that 'for some patients this might be best provided by a community service or via a telephone appointment'.