Thousands of schools across England and Wales faced disruption and closures today as teachers stage a one-day national walkout.
The strike, called by the National Union of Teachers in an ongoing row over pay and conditions, could force some schools to close to some or all pupils.
The action has been condemned by the Department for Education (DfE) which says it will disrupt parents' lives and damage children's education.
NUT members are expected to join picket lines across both nations, with the union also holding a number of rallies.
One website, Emergency Childcare, said it had seen a 50 per cent rise in the number of bookings it would get for an average Wednesday, which it said showed the impact of the walkout on families.
The NUT's ongoing industrial action focus on three issues – changes to pay, pensions and workload.
NUT Kent divisional secretary John Walder said teachers needed to "stand up and be counted".
He told News Shopper: "This is not only their future but the future of thousand of kids in Kent.
"Even now in the county there are well over 100 vacancies and at least 15 headships unoccupied so there are schools not being run properly.
"The only thing I've heard from parents is a letter in absolute and total support of what we are doing.
"We don't want kids to be off school but in the long term we are talking about the future of education for their children."
Teachers are meeting outside the Three Daws Pub in Gravesend at 10am before a rally at St Thomas' Hall in Canterbury at 10.30am.
Click here for a list of closed and partially closed schools in Kent.
NUT deputy general secretary Kevin Courtney said the strike was a "last resort".
He said: "We have been trying to persuade Michael Gove to change his mind, he is unwilling.
"Michael Gove's policies are exhausting and demoralising teachers and that's very bad and disruptive for education.
"Thousands of good people are leaving the profession, we are building up to a teacher shortage and our children deserve energetic and enthusiastic teachers not demoralised and exhausted ones."
Mr Courtney added the union wants the Education Secretary to change his policies on school accountability, which the NUT says is leading to "enormous" workloads for teachers, performance related pay and pensions.
The DfE has said parents will "struggle to understand" why the NUT was pressing ahead with its strike.
Greenwich parents can find out the situation at their child's school here.
A spokesman said: "They called for talks to avoid industrial action, we agreed to their request, and talks have been taking place weekly.
"Despite this constructive engagement with their concerns, the NUT is taking action that will disrupt parents' lives, hold back children's education and damage the reputation of the profession."
And David Cameron's official spokesman has said the Prime Minister would call on teachers not to strike because the action "disrupts children's education and children's families."
Andy Major, operations manager at Emergency Childcare said the strike is set to leave working parents with a problem.
The firm had seen a "massive influx" of emergency bookings, he said.
Full list of contact details for Lewisham schools here.
Mr Major added: "The strike will undoubtedly have a big impact on businesses whose staff will not have a back-up plan in place, forced to take time off to look after their children."
Mr Gove has written to seven union bosses setting out the progress he believed had been made in an ongoing programme of talks between the DfE and these teaching unions.
In it, he said he wanted to underline his commitment to the talks process.
But the NUT said the letter showed how little progress had been made in the talks.
The NUT has been embroiled in its current dispute with the Government for more than two years, and staged a series of regional strikes with the NASUWT teaching union last year. Between them they represent the vast majority of teachers.
A proposed one-day national walkout in November by the two unions was called off and the NASUWT has decided not to take part in the walkout.
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