Political parties and civil society groups have signed the Good Systems Agreement calling for reforms to the UK's voting system.
The agreement, prepared by Making Votes Matter, calls for the first-past-the-post system to be replaced with proportional representation.
The Green Party, Lib Dems, the Brexit Party, Plaid Cymru, SNP and the Women's Equality Party are calling for a citizens' assembly to be set up to develop the new system.
Cllr Jonathan Bartley co-leader of the Green Party? said: 'It is very tempting to blame individuals for the disastrous state of Britain today, the Brexit chaos, the poverty and inequality, the insecurity and mental health crisis, the dreadful state of our natural world and the climate chaos. But it is clear that the failure is systemic.'
Speaking at the LGA annual conference, Cllr Bartley said there needs to be a 'radical' shift of power to tackle the challenges facing Britain today.
'Local government is not democratic because it isn't allowed to be by central Government,' he said.
He joined the call for a 'fairer' voting system at a local level, backed up by a written constitution.
He also said democracy used to be called Localism until Eric Pickles 'derided the word into oblivion'.