Thousands of activists are staging a protest outside the Conservative Party's annual conference to highlight campaigns including the impact of austerity cuts on workers.
Union leaders and officials from campaign groups including CND will address the rally in Manchester and will attack Government policies.
In a speech, TUC general secretary Frances O'Grady will criticise the controversial Trade Union Bill, which introduces fresh restrictions on strike ballots, picketing and union funds.
Delegates have been warned not to wear Conservative-branded badges and lanyards when walking around Manchester, over fears that protesters may target them.
Everyone attending conference is required to wear the official passes, but in an email to attendees, party chairman Lord Feldman said it was "particularly important" to remove them when outside the secure zone, in order to avoid making themselves a potential target for troublemakers.
Asked if this was a "sad" state of affairs, Prime Minister David Cameron told BBC One's Sunday Politics: "No, not at all. I think all my party members will enjoy very much being in Manchester.
"There are a lot of demonstrations planned, and obviously people need to take care in respect of that, but people will be enjoying all that Manchester has to offer."
Protestors are gathering around Oxford Road in Manchester for the start of a protest against government policies as the Tory conference formally opens. Thousands are expected.
Greater Manchester Police say they have shut down a 'protest rave' which has been taking place in the city centre for the last 48 hours.
At around 8.30am this morning officers entered Piccadilly Gardens and began to disperse the people who had gathered.
Officers say there had been a significant number of complaints from residents, businesses and local councillors since Friday evening.
Two people have been arrested for obstructing police officers.
Four men have been charged with drug conspiracy offences following a huge seizure of drugs in Liverpool. They were arrested during an operation in Garston on Friday, which was led by detectives from Titan, the north-west's regional organised crime unit. The four are charged with conspiracy to supply cocaine, conspiracy to supply ecstasy, conspiracy to supply amphetamine, and conspiracy to supply mephedrone. They will appear before Liverpool Magistrates Court tomorrow. A fifth man arrested has been released on police bail pending further enquiries.
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.
Police are continuing to question five people after the discovery of drugs with an estimated street value of £25 million at a flat in Liverpool.
The drugs, believed to be mephadrone and amphetamine, were found within a ground floor flat in Garston yesterday.