Union leaders and officials from a range of campaign groups will address a rally and attack government policies after the Tory conference formally opens in Manchester today.
The protest is due to start at 12.30pm.
A handful of demonstrators had already gathered, staging a noisy protest outside the secure zone surrounding the Midland Hotel and Manchester Central conference centre, as delegates arrived on Saturday.
Alongside the unions, the demonstration is expected to be attended by among others, the CND and members of the Royal College of Midwives, as well as some Labour party activists.
Frances O'Grady, the general secretary of the TUC, will be among those speaking and is expected to criticise the government's controversial Trade Union Bill, which introduces fresh restrictions on strike ballots, picketing and union funds.
The Conservative's party conference will be the first autumn conference of a majority Tory administration since 1996.
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