Media playback is unsupported on your device Media caption TUC chief Brendan Barber: "The poorer you are, the more you lose"

The public will not accept large-scale spending cuts, TUC chief Brendan Barber has said as trade unions gather in Manchester.

Mr Barber said unions would reach out to the wider community to form a "progressive alliance" to make the case for alternatives to spending cuts.

And RMT union leader Bob Crow called for a campaign of "civil disobedience" in protest at spending cuts.

Ministers say they must take action to tackle the £155bn budget deficit.

Without "decisive action", Chancellor George Osborne argues that Britain's economic stability and reputation would be put at risk.

Rich 'let off'

He has asked all departments, excluding the NHS and international aid, to find four-year cuts of between 25% and 40%, to begin in April 2011.

But his plans are expected to come under fire at the gathering of trade union members in Manchester for the TUC Congress this week.

TUC general secretary Mr Barber has already accused the government of "making struggling families bear the cost of the recession, while the rich have been let off".

He said a study commissioned by the TUC suggested that the bottom 10% of workers will suffer cuts in services equivalent to 20% of their household income, while the richest will lose the equivalent of just 1.5%.

"Voters last May did not vote for a radical and permanent cutback in the scale and scope of public services," he said.

'Unfair'

"Now the poll tax - that was defeated when the decent majority stood up and said 'no'. It offended the deep sense of fairness that we share in this country, indeed across party divides.

"The cuts have only just started to bite, when their full extent becomes clear I know that the country will join with us in saying 'no' once again to policies that are so eye-wateringly unfair".

Media playback is unsupported on your device Media caption RMT union leader Bob Crow on bank bonuses and police numbers

It followed warnings from Mr Crow, general secretary of the Rail, Maritime and Transport Union, that unions would fight for their members' rights.

The RMT is asking the TUC to back calls for co-ordinated industrial action "to defend jobs, pensions and conditions".

Mr Crow told journalists he envisaged a civil disobedience campaign with people taking to the streets with stunts such as "Batman scaling parliament and Spiderman going up Buckingham Palace".

The union leader may have been referring to a high-profile campaign waged by the Fathers For Justice group in which a protester dressed as the comic-book character scaled Buckingham Palace.

Earlier Mr Crow said if there was a "concerted effort by this new government to attack workers in all different parts of society" then workers taking action should "co-ordinate that resistance to defend working men and working women".

Mark Serwotka, general secretary of the Public and Commercial Services Union, said industrial action was "inevitable" but added: "It is clear the most effective opposition would be the biggest popular movement we have seen for many years."

BBC political correspondent Reeta Chakrabarti, at the TUC in Manchester, said there were those who wanted to send out an aggressive message against cuts, and others who feared trade unions would be portrayed as political dinosaurs.

'Feel militant'

She said Mr Barber was trying to set the tone and steer a course between the two, seeking a general alliance between public sector workers and wider public opinion.

But she said no-one was talking about a general strike - which unions cannot organise as they each have to ballot their members separately.

Instead unions such as the PCS and Unison were talking about more formal links to co-ordinate action like demonstrations and campaigns.

Labour's leadership candidates will attend a hustings at the TUC conference - hoping to attract union members' support before the winner is named on 25 September.

Tackling the enormous deficit that Labour left us with is essential to underpinning the economic recovery. Danny Alexander, Chief Secretary to the Treasury

The current acting leader Harriet Harman told BBC One's Andrew Marr Show her party backed the right to strike, but "no one wants to see strikes" - including public sector workers.

But she said she expected local communities to campaign alongside trade unions when public services were threatened.

She added: "We feel very concerned indeed, yes, about threats to jobs and we don't accept the argument that somehow this is entirely necessary to cut the deficit at this speed. We think it's actually a threat to the economy.

"And the arguments that the 'Big Society' can take the place of public services are we think are disingenuous. So to that extent yes, we do feel militant about it."

But Chief Secretary to the Treasury Danny Alexander told Sky News: "Tackling the enormous deficit that Labour left us with is essential to underpinning the economic recovery.

"If we don't do that in the way that the Labour leadership candidates - who seem to be in denial about the mess that they left the country - would say, then we would end up in a worse economic position than if we took the action we are taking to reduce the deficit."

He said the government was taking action to encourage a private-sector led recovery and the spending review - which will detail where the axe will fall - would be spread over four years.