Local government united in cross-party opposition to ministerial proposals to bypass councils with new-elected public service bodies, at Tuesday's general assembly.
Labour, Conservative and Liberal Democrat leaders said plans for elected foundation hospital boards and ideas on similar structures for the police and other services, constituted a new centralism.
In a debate on the LGA's summer review Ambition Thwarted, chairman Sir Jeremy Beecham said the government's agenda risked deepening 'silo democracy', jeopardising joined-up work by creating competing centres of legitimacy in each service area.
He said the government's version of localism was managerial rather than political, and sought to disempower locally elected politicians in the name of empowering their constituents to run services themselves.
According to Sir Jeremy: 'There is a limit to the capacity of people, particularly in areas of multiple deprivation, to assume these responsibilities.'
Councils were needed, he said, to mediate conflicts and ensure equity.
Conservative vice-chairman Sir Sandy Bruce-Lockhart went even further and said multiple elected bodies were a threat to local democracy.
He said: 'Either the government believes in a localism that by-passes local government to foundation hospitals or directly elected police boards or it does not. Either it believes in democracy or it does not.'
Echoing the title of the review, he said local government had proved its ambition to improve public services through CPA, but had been thwarted by the government's refusal to deliver its side of the bargain in increased freedoms.
He said the biggest offenders were the Department of Health, through its plans for bed-blocking fines, and the Department for Education and Skills, notably in the recent school funding crisis.
Liberal Democrat leader Chris Clarke said the government's original charge during the crisi s - that LEAs withheld £500m from schools - was an 'unforgivable lie'.
Mr Clarke, who also criticised plans for new elected bodies, added: 'When things go wrong their instinct is to stick it to us.'
Sir Jeremy said that it was vital, with the main parties starting to formulate their platforms for the next election, for the LGA to lobby hard for its version of new localism to triumph over the government's variant in their manifestoes.
In an echo of former Liberal leader David Steel, he said: 'Let us go back to our town halls and prepare to fight for local government.'
Lord Herman Ouseley, who was re-elected as LGA president unopposed, joined in the attack on ministers. He set the government five tests for truly localist policies: they should empower locally elected politicians to set local priorities, provide resources for these, support councils in their achievement, enhance existing freedoms and be subject to full LGA consultation.
Independent leader Milner Whiteman sounded a different note, saying districts councils - currently undergoing CPA - were particularly at risk of 'initiative fatigue' from government, and were 'encountering problems keeping up with their larger counterparts'.
Deputy prime minister John Prescott and chancellor Gordon Brown, seen as the most local government-friendly cabinet ministers, were due to address the conference today.