BMA analysis of STP proposals found that NHS organisations will need at least £9.5bn of capital funding to invest in the infrastructure needed to get their plans off the ground.
Responses from 37 of the 44 STP 'footprints' across England show that 'projected capital demands' for these areas alone total £9.53bn.
The BMA says that more than half of STP footprint areas have told NHS England they need over £100m in up-front funding, while areas including Manchester, Cambridgeshire and Peterborough and West Yorkshire estimate that they will need more than £500m.
But the BMA says pressure on budgets means that 'NHS leaders are unlikely to have anything like the capital required' to deliver STPs.
The union warns that an annual capital allocation of £4.8bn handed to the DH from 2016/17 to 2020/21 in the latest spending review is 'being transferred to cover vast hospital deficits and will be soaked up by other demands'. It cited evidence given to a House of Commons public accounts committee hearing last month by NHS Providers that £1.2bn of the capital budget had been used ‘to prop up revenue’.
A report on NHS finances presented at NHS England's latest board meeting last week showed that almost half of CCGs were reporting 'year to date overspends'.
BMA chair Dr Mark Porter said: 'From its very beginning this process was carried out largely behind closed doors, by rushed health and social care leaders trying to develop impossible plans for the future while struggling to keep the NHS from the brink of collapse.
'These figures are especially concerning given that everyone can see a huge crisis unfolding within our NHS, with record numbers of trusts and GP practices raising the alarm to say they already can’t cope. The NHS is at breaking point and the STP process could have offered a chance to deal with some of the problems that the NHS is facing, like unnecessary competition, expensive fragmentation and buildings and equipment often unfit for purpose, but there is clearly nowhere near the funding required to carry out these plans.
'These plans are fast becoming completely unworkable and have instead revealed a health service that is unsustainable without urgent further investment, and with little capacity to "transform" in any meaningful way other than by reducing the provision of services on a drastic scale.'
An NHS England spokeswoman said: 'Rather than just commenting from the sidelines, local health and care leaders and clinicians are coming together to actually try and solve some deep-seated problems by identifying practical ways to improve services. Yes, there are well known pressures and constraints facing the NHS, but for patients' sake we should obviously all try and make the best of the situation, rather than just stand to one side and say: "Well I wouldn't start from here".'