Thousands of school and college students are expected to stage walkouts this month as part of a growing wave of occupations and demonstrations planned to support the co-ordinated strike action organised by trade unions.

Students behind last year's demonstrations against cuts to post-16 education are mobilising in schools and further education colleges as part of a wider campaign to turn 30 June into a national day of action against the government's austerity programme.

The move follows the announcement this week by the direct action group UK Uncut that it would be joining picket lines and staging a "public spectacular" in London to coincide with the industrial action.

Michael Chessum from the National Campaign Against Fees and Cuts, one of the student groups behind last year's protests, said: "It was the student movement before Christmas that really kicked many of the major unions into action, and we'll be there again in force on 30 June. One of the successes of the student movement was that we abandoned passive, A-to-B marches in favour of direct action in the streets and on campuses. Mass strike action is the logical extension of that. We're not here to protest; we're here to actively resist."

More than 750,000 public sector workers from major unions including the Public and Commercial Services Union, the National Union of Teachers and the Association of Teachers and Lectures are expected to take part in this month's industrial action. The strike, which will be the largest in the UK for several years, is expected to bring schools, colleges, universities, courts, ports and jobcentres to a standstill, and comes as millions of staff face pay freezes, job losses and pension reforms.

Activists say the wider campaign of demonstrations, occupations and walkouts will build a broad coalition of people opposed to the government's programme of cuts and has been inspired, in part, by protests across Europe over recent months – particularly those in Spain and Greece.

As part of the preparations, anti-cuts groups have held a series of "J30 assemblies" across the country under the "generalise the strike" slogan, to plan events and mobilise support.

Over the next few weeks, assemblies will be held in Birmingham, London, Leeds, Newcastle, Norwich, Sheffield and Sunderland. Another group, Right to Work, says it has organised more than 40 events to coincide with the strikes.

One of the organisers of the J30 assemblies, Alex Long, said they had been strongly influenced by protests held in Spain last month. "We want to approach this whole 30 June strike day in a more general way, to use it as a general day of action against the cuts," he said.

In London, activists say they are planning a number of direct action campaigns on 30 June, with events in the City of London and Westminster, including Oxford Street. There is also a call to occupy Trafalgar Square and a Facebook page calling for people to join a "black bloc" protest (the black bloc being the group blamed for smashing up shops during the TUC demonstration in March).

Tens of thousands of students from further education colleges and schools took part in last year's demonstrations against the rise in tuition fees and the scrapping of the education maintenance allowance, and activists hope many will walk out of classes at the end of this month.

Campaigners have been leafleting colleges and schools, calling on students to hold meetings, make contact with teachers who are union reps and organise walkouts on the day.