A teacher says she reluctantly joined strike action because she can no longer afford to heat her flat in Essex.
Members of the National Education Union (NEU) have started a two-day strike in an ongoing dispute over pay and conditions.
One of those walking out is Steph Bird, a geography teacher at the Plume Academy in Maldon, Essex.
She has been a teacher for two years, but says the pay is not enough to cover the increase in the cost of living.
"At the moment, I've gone through winter in a cold flat, heating just one room," said Miss Bird.
"I'm going back to a flat that I can't heat, that's cold, and sitting at a desk writing and planning for the next day.
"I have three qualifications. I have a degree, I have a masters, and I have my PGCE.
"I have three sets of qualifications, I'm a professional woman and I'm unable to afford to live alone as a single person in a town where it should be affordable for professional people to be living."
Miss Bird says she loves her job working with "brilliant young minds", but warns there will come a time when teachers like her will have to find work elsewhere.
Other teachers also agree that underfunding means many are leaving, or thinking about leaving the profession.
Natalie Foster says education has been "continually underfunded" ever since she started the job 22 years ago.
"If you think back to a time when you were in school, you had a teacher that inspired you and encouraged you and always gave you another chance," said Ms Foster.
"Those people are impacting students' lives every day and if there continues to be underfunding, if there continues to be a recruitment crisis, then those people won't be there to support our young people."
Molly Doyle, teaches Spanish at a high school in Cambridge and says pay is one of the biggest problems for her.
"I don't have enough every month to pay the rent to live in Cambridge - and the funding for schools, in general, is just a real problem," Ms Doyle told ITV News.
She also said she's having to buy equipment for students.
Ms Doyle said: "I have to buy my own pens for my classroom because we don't have pens to give to the students.
"Being a teacher is the best job and I really enjoy it but I just see all the things that are making it hard for me and for the students and I just feel exhausted."
The Education Secretary Gillian Keegan said industrial action will mean more disruption to children’s education.
"I want to get around the table and engage in serious talks on teachers’ pay and other issues to resolve disputes," she added.
"My only condition was that strike action is paused so those discussions can take place in good faith and without disruption."
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