A huge shake-up of Britain’s welfare system aimed at streamlining benefits gets under way Monday with jobcentre staff expected to stage angry protests.

People living in Ashton-under-Lyne, in Greater Manchester, can apply for the new Universal Credit from today in a trial of changes which will be rolled out across the country within four years.

The new credit will replace income-based jobseeker’s allowance, income-related employment and support allowance, income support, working tax credit, child tax credit and housing benefit.

The Public and Commercial Services (PCS) and Unite unions, which represent staff in jobcentres, are planning to protest in the town, accusing the government of “demonising” jobless people.

Work and Pensions Secretary Iain Duncan Smith said the move was the start of a “fundamental cultural shift” to ensure people are better off in work than on benefits.

Around 7,000 people are expected to claim Universal Credit during what the government has dubbed the “pathfinder” period in certain parts of northwest England which also include Oldham, Warrington and Wigan.

A national roll-out will begin in October, with the changes expected to be implemented across the country by the end of 2017.

But unions argue more needs to be done to support jobseekers into work, while critics have also raised concerns about the online application process, said to rely on a complex computer system.

PCS general secretary Mark Serwotka said: “If universal credit was being introduced to genuinely make life easier for people entitled to benefits it would be commendable, but the government’s pernicious language exposes its real intent is to demonise and punish them.