A strongly-worded motion backed by LMC leaders last week set out a series of reasons why STPs were 'fundamentally flawed'.
GP representatives agreed that the process was run by 'undemocratically appointed quangos' that did not represent GPs or the public, that they were 'an attempt to dismantle the NHS' and that they would increase the postcode lottery for NHS services.
GPs agreed that STPs would create divisions between NHS organisations and inevitably lead to 'cuts and/or longer waiting times'.
The LMCs debates come after strong criticism of STPs from both the GPC and RCGP in recent months.
The RCGP said earlier this year that many STPs should be rejected because they failed to address the growing GP crisis. The BMA said in February that the NHS financial crisis was making many STPs unworkable.
Mid Mersey LMC medical secretary Dr Ivan Camphor told the conference that STPs were not the answer to the crisis facing the NHS.
'They are not inclusive. Cheshire is being asked to save £1bn by 2020. There is very little, if any, GP engagement at the top. These are plans designed by acute trusts, and the savings will be done by general practice.'
He warned that GPs needed to stand up and say that STPs were not acceptable before they had a major impact on the profession.
One speaker warned that many of the aims of STPs were issues the NHS did need to face up to, around integration and decisions on what is the best location to provide certain services from. He urged GPs not to condemn the ambition of STPs, but to focus their complaints instead on the process - and the failure to engage properly with the profession.
But Dr Rami Eliad, of Hertfordshire LMC, told the conference that STPs were plans that had been 'parachuted down' and that they simply did not add up.
'Their main aim is cutting costs,' he said. They offer 'token support to community services' but are primarily financially driven, he warned. 'They pay no heed to [the fact that] reduction of acute beds will not result in reduction of acute care - it will result in bottlenecks.'
Birmingham LMC GP Dr Samir Dawlatly urged GPs not to vote for 'sentimental' motions condemning STPs, warning that condemnation of the plans would make it impossible for the GPC to work with them. But GPs voted strongly in favour of motions severely criticising the STP process.