The coalition's spending cuts will hit the poorest in society 10 times harder than the richest as the health, social and education services they rely on are slashed, an extensive new study for the Trades Union Congress has found. The TUC general secretary, Brendan Barber, says the research proves that the Conservatives are breaching their election promise to introduce cuts fairly.

Lone parents and pensioners will suffer the most from the public spending cuts, the study finds, with everyone but the top 10% of earners losing more from cuts than from tax and benefit changes. Barber told the Guardian that the study, which will be unveiled on Monday as the TUC meets for its annual conference in Manchester, proved that the Conservatives had betrayed their election promises to protect frontline services and ensure any cuts are fair.

"It's a real threat to social cohesion," Barber said. "Public services are a part of the glue that holds society together. This mantra that the Tories followed, 'we're all in this together' – public services are a part of being a shared community. When you start weakening the seams you threaten the fabric of society."

The TUC intervention comes as the coalition leadership struggles to contain a row over the announcement by the chancellor, George Osborne, of £4bn in welfare cuts and amid warnings from the Police Federation that 40,000 frontline police jobs are at risk if they go ahead with the cuts suggested. The Treasury is now at the height of the negotiations with ministers over the next public spending round, with departments jockeying to protect their budgets from the worst-case 40% cuts.

David Cameron and Nick Clegg must also face their parties at the forthcoming party conferences to justify the government's decisions and maintain unity across the coalition. That will be tested on Monday when Osborne will be called to the Commons to answer an urgent question from Bob Russell, a Liberal Democrat who objected to Osborne's assertion that he would reduce the number of people who claim welfare benefits as a "lifestyle choice". Russell, the MP for Colchester, told BBC Radio 4's Today programme: "Yes, let's deal with the welfare cheats. But the notion that they are responsible for all the ills of the nation is in fact a smokescreen and it's not very ethical."

The research predicts the impact of the cuts across the country using publicly available data profiling the services people use, from healthcare to education and transport, and the planned cuts. It shows the profound effect the deficit reduction plans will have on families and lone parents in particular.

Excluding benefit cuts, single people will lose the equivalent, on average, of £817 a year in services, while a couple with no children will lose £1,012 and a single pensioner £1,017. A lone parent, meanwhile, will lose £1,880.

Osborne promised at the time of the budget in June that his plans would be fair and hit the richest hardest. In the dying days of the election campaign, Cameron also guaranteed that the cuts agenda would not affect frontline services.

Barber said that Liberal Democrats had fundamentally changed their position on the economy to secure a place in the coalition, but he also questioned the Conservatives' mandate. "Have they got a mandate? Not with a proportion of thirtysomething per cent of the votes. I don't think there was a clear mandate for savage cuts of the sort we're going to see.

"One of the key things they said was that their intention was to make the necessary changes to reduce the deficit, but in a way that would be fair, would protect the most vulnerable, and so on. Yet what is already clear … from the cuts that have already been decided on [is that] the impact is overwhelmingly on people at the bottom. This piece of work will demonstrate that. That will be magnified dramatically when we see an even bigger programme of cuts with the comprehensive spending review. On that absolutely core issue they will be absolutely in breach of what they committed to when they were campaigning in the election."

The TUC will launch a campaign next week to convince the public that the spending cuts are excessive and unwarranted, but Barber said it would not be calling immediately for a general strike. "There is potential for real disputes. We've got this whole cocktail of issues coming together: a pay freeze, potentially significant job losses … privatisation and restructuring.

"All of that adds up to a hell of an agenda of issues that could give rise to pretty difficult disputes, of course it could, but this campaign is about mobilising opinion and popular support across the community as a whole. It's a campaign to try to win political support and make people realise that although at the moment there seems to be public support there won't be that public support once the reality dawns of what it actually means."