Teachers have threatened further industrial action as a national strike hit up to 9,500 schools across England and Wales on Thursday.
Members of the National Union of Teachers said they “felt no guilt” following the walkout that saw more than one million children turned away from lessons.
Some picketed outside schools in protest at the Government’s 2.45 per cent pay offer this year, which they claim is a real-terms cut following a huge rise in the cost of living.
Others marched through cities including London, Birmingham, Cardiff, Manchester and Liverpool as part of official rallies.
Activists said they were prepared to walk out again unless the Government caved in to their demands for more pay. One said another strike could take place this term, although it is believed to be unlikely.
Members of other classroom unions, who refused to back the strike, said it could herald a return to 80s-style militancy, when a wave of industrial action caused widespread resentment among parents.
John Dunford, general secretary of the Association of School and College Leaders, said: “This strike puts the teaching profession into a corner that we have not been in for 20 years’.”
Ed Balls, the schools secretary, said the timing of the strike – days after the Easter holidays and as pupils are preparing for exams – was “unfortunate”.
Visiting a school in Dartford, Kent, Mr Balls said: “I don’t think it’s supported by most teachers.”
Only one in 10 of the country’s 400,000-plus teachers actually voted to strike, the Government said.
Further education colleges were also forced to close or operate on reduced timetables after members of the University and College Union joined the strike.
Rank-and-file NUT members insisted they would be prepared to walk out again.
Up to 7,000 members of the NUT, UCU and the Public and Commercial Services union, marched through Westminster.
Alex Kenny, an NUT delegate from east London, said: “We are not ruling out further strikes and indeed could see another one this term. If the Government don’t listen this time round we’ll just have to do it all over again. If the other teaching unions begin balloting their members about a further strike then the NUT will do the same and teachers will strike.”
Christine Spragg, a teacher at Andrew Ewing Primary School, Hounslow, west London, added: “Everything is going up except our wage. Unless it changes we will all come out here in force again.”
Teachers picketed the City Academy School, Bristol, to stop staff working.
Keith George, a science teacher, said: “We have already turned several teachers away. It has been very satisfying that our message appears to be getting through.
“If parents want the best teaching for their children then this strike is essential.”
Paulette North, the NUT’s assistant divisional secretary, said: “We do not feel guilty at all. In fact we feel that if we do not have these strikes then we will lose even more teachers than we are already.”
Despite union guidance requesting teachers not to picket outside schools, some members also protested at the entrance to Lawnswood School, Leeds.
Dennis Gibbons, an NUT official from Leeds, said: “There is a recruitment crisis looming in the teaching profession.”
Phillippa Arnell, an English teacher at Park Community School, Leigh Park, Havant, Hants, said 21 NUT members were on strike – a third of the teaching staff. Lessons were being covered by support staff, she said.
“I did feel guilty when I explained to my pupils about going on strike but we just want to be treated fairly,” she said.