Manchester anti-austerity march October 2015
Anti-austerity protestors marched through Manchester during the start of the Conservative Party's annual conference @captiveanimals/Twitter

The Conservatives are battening down the hatches, as anti-austerity protestors plan are rallying in Manchester at the start of the party's annual conference. Barriers have been erected around Manchester Central and the Midland Hotel – in what some activists have described as a "ring of steel" – in bid to stop any of the 80,000 protestors organisers expect to show up infiltrating the political party's annual bash.

The demonstration has been organised the Trades Union Congress (TUC) and thousands of members from the UK's largest unions, Unite and Unison, are expected to be in attendance. The protestors are particularly infuriated with the government's draft law to impose a minimum turnout for strike ballots held by trade unions.

The Conservative administration has argued that the move would curb the power of the unions and stop essential public sector services from by crippled by walkouts. But the unions have described the Trades Union Bill as undemocratic and have vowed to fight the proposal.

"The government's Trade Union Bill is about shifting the balance of power in the workplace and silencing union opposition to cuts. Its measures go well beyond changes to how strike ballots are carried out," Frances O'Grady, the general secretary of the TUC, will say.

"For the first time since the 1970s, bosses will be able to bus in agency temps to break a strike. This will make strikes less effective and reduce workers' bargaining power. And it could mean agency workers without proper training and proper support delivering important services that we all rely on."

She will add: "The bill will impose stifling restrictions on peaceful pickets and protests. Unions will be forced to tell the police and employers what they are planning to put on Facebook 14 days beforehand. If they make a mistake they could be fined up to £20,000 a time.

"And if union organisers forget to wear an armband on a picket line, employers will be able to rush to the courts to get the strike called off. The British people don't want their police officers monitoring what trade unionists post on social media or checking if they are wearing the correct armband. They want them out there catching the real criminals."

The comments will come ahead of speech by Labour's new leader Jeremy Corbyn at a People's Assembly rally at Manchester Cathedral on 5 October. The left-winger had previously echoed the words of Conservative backbencher David Davis by comparing the Trades Union Bill to anti-union measures introduced by Spanish dictator General Franco.

"The burdens they are placing, as one Tory MP admitted, is actually the strategy used by General Franco in Spain. They seem to still think that it's right just to attack trade unions because they exist. I'm proud to be a trade unionist – that's why we are going to fight this bill all of the way and when we have been elected as a majority in 2020, we are going to repeal this bill and replace it with a workers' right agenda," he told the TUC in Brighton on 15 September.