The slow hand-clapping was started by Conservatives. A handful of Labour members briefly joined in, but it was quickly overwhelmed by noisy applause from Labour loyalists.
Answering questions after her speech, Ms Armstrong prompted derisory hoots from the delegates when she claimed the government was being flexible over the introduction of new political structures for councils.
Referring to the three models laid down in the Local Government Bill, she said: 'I don't see them as three options, I see them as three broad frameworks with a huge amount of flexibility. There is no blueprint from the Bill, and the new fourth option does give you even more flexibility.'
In a faltering speech which failed to impress delegates, Ms Armstrong said: 'Central government has to better understand the need for local diversity. That is the discussion we are having at national level.'
She highlighted the power of community initiative in the Bill, and urged councils to 'stretch those powers in the best interests of your communities'. She said the new power was 'at the centre of giving local government that powerful role over the next decade. It underpins all the other changes'. Ms Armstrong did not mention mayors once.