She asserted Labour's commitment to local autonomy: 'Our shared ambitions can never, will never, be delivered simply by controlling the levers in Whitehall.
They can only be delivered in partnership, with local communities fully engaged, with all agencies working together harnessing the contribution of private sector partners, the voluntary sector and faith communities.'
Ms Armstrong stressed the need for 'strong local leaders [who are] more effective, more visible, less bureaucratic, dynamic leaders making a difference locally', as the only way to include more people in the country's prosperity.
'That's why we have acted to strengthen local leadership - mayors and cabinets will have more clout,' she said.
She warned delegates their roles would be almost extinguished by a Tory government.