Cuts to GPs' core pay will be compounded by the biggest overhaul of QOF since its inception, which GP leaders fear could slash a further £15,000 on average from practices.
Ministers are threatening to impose the changes - which the GPC says will bring the biggest pay cut for GPs in almost a decade – after contract negotiations collapsed.
The imposed deal could also force a split in the UK GP contract, after the Scottish government opened talks with GPC Scotland on a breakaway deal.
The government is offering a 1.5% funding uplift that the GPC says is 'dwarfed by the negative impact of other elements of the proposal', which would create a huge increase in work. GP leaders had argued for an uplift that would cover rising expenses and offer GPs a 1% increase in take-home pay.
Details of the contract plans were set out in a letter to PCTs and SHAs by NHS Commissioning Board commissioning lead Dame Barbara Hakin.
The letter marked the start of a 13-week public consultation period, which ends in January, after which the DH will be legally able to alter the GP contract unilaterally.
MPIG will be scrapped over a seven-year period starting from 2014 under the plans.
Dame Barbara's letter said a single weighted capitation price would be calculated 'based on current average expenditure on global sum payments, correction factor payments and basic elements of PMS funding'.
She confirmed both GMS and PMS practices would move to this over seven years.
The BMA has always argued that MPIG must only be phased out on a 'rising tide' basis, with practice funding levelled out through increases to all practices' funding, rather than redistribution of existing funding.
GPC chairman Dr Laurence Buckman confirmed the DH proposals would create 'winners and losers'.
Laurence Slavin, a partner at specialist medical accountants Ramsay Brown & Partners, told GP that practices could face 10% swings in funding, worth around £100,000 on average.
'A lot of practices rely on their correction factor. These are either practices previously in deprived areas which were in receipt of the deprivation pay from the Jarman Index, or practices which were doing more than most, earning high amounts of items of service, whose income is maintained through the correction factor. The former may be protected by a promise of extra funding for deprived practices, but the latter will suffer the loss,' he said.
Fresh talks on the deal look unlikely after the BMA said it would 'not legitimise them by returning to the table'.
Health secretary Jeremy Hunt has called the deal fair for GPs.
Expert view: The accountant
Laurence Slavin, a partner with accountants Ramsay Brown & Partners, reacts to plans to overhaul the GP contract
'Proposals to overhaul the QOF are irritating and pernicious but not catastrophic. The potential changes to the global sum, however, are catastrophic. The history is enormously important to keep in mind. The 2004 contract was underpriced and the DH had to come up with a quick fix to give GPs the funding they needed – and actually only at the level they were earning in 2002/3, so it only put them back to the position they were in before.
'This is the background to the MPIG and the correction factor, like a sticking plaster on a sinking ship. The sticking plaster has worn out, as we all knew it would.
'But any replacement has to address the issue that its predecessor was there to protect GPs' earnings at their previous level. It can't just be disposed of as an inconvenience. If it is, GPs' earnings will be undermined for years to come.
'So while I was cautious over industrial action on pensions, I am not cautious over this. Make sure the negotiators are concentrating on this, dust off the barricades and fight. This is the issue.'