By Katherine Sellgren BBC News Online education staff

Classes for thousands of pupils across London are cancelled on Tuesday as teachers stage a one-day walk-out over cost-of-living allowances.

But primary school teachers Margarita Taylor and Karen Smith, say there is little alternative but to go out on strike.

Margarita Taylor is not struggling to live in London on her annual salary of �34,000.

But she supports the campaign for more money for London teachers because the problem of recruiting staff is making her life - as a member of her school's management team - stressful and demoralising.

Margarita, who has been teaching for 10 years, is in charge of cover and supply teachers at Ilderton Primary in the London Borough of Southwark.

Margarita Taylor: We cannot fill vacancies

She has three teachers about to take maternity leave and has had no joy in filling any of the vacancies.

"There are no teachers around - we put adverts in the Times Educational Supplement and we get no response," says Margarita.

"We've been advertising these three jobs for the past month and we still haven't had any replies."

Margarita says her school is not a problem school and has been described by Ofsted as "a very good school".

"We have no trouble here," she says.

But she says many potential recruits are put off by the cost of London living.

"I'm not surprised because I know other schools are having even more trouble recruiting than we are, but I'm upset that we can't get the staff."

Moving out

Margarita's colleague, Karen Smith, has spent all her eight years as a teacher in London schools.

I actually do want to teach in London, but financially it's becoming quite difficult

Karen Smith

But she is still in rented accommodation and doubts she will ever be able to afford a mortgage in London.

"I'm looking to move out of the capital within the next few years - I don't want to be renting for ever, but I don't see how that will change if I stay in London," says Karen.

"I actually do want to teach in London, but financially it's becoming quite difficult.

"Basically I just feel there aren't many incentives left to stay teaching in London.

"Offering money won't solve it overnight, but it would help."

'No option'

Karen and Margarita, both members of the NASUWT, make no apology for the one-day strike, saying pupils would be worse off if teachers failed to highlight the problem.

"At least we're drawing attention to the problem - if nothing is done, there will be lots of pupils without a teacher in the future," says Karen.

"All these supply teachers being brought in - what does that do for the education of the children? That's not going to improve the SAT results for the government," says Margarita.

For her the strike is a last resort.

"This is to make a noise because the government is not listening.

"I'm very angry with the government - their priority for education, education, education seems to have changed to money, money, money," she says.