FACTBOX-The NUT national strike

LONDON (Reuters) - Thousands of schools are set to close on Thursday as teachers stage their first national strike for two decades.

Here are some facts about the strike:

WHO IS STRIKING?

The one-day strike, the first for 21 years, involves teachers from the National Union of Teachers (NUT), which has about 200,000 members. They voted by 3 to one in favour of the industrial action. However no other teaching union is striking.

The Local Government Association (LGA) estimates that, as there were about 432,000 full time regular teachers in January 2007, about 11 percent of the regular school workforce had voted for action.

WHAT IS THE STRIKE ABOUT?

The government announced in January it would increase teachers’ pay by 2.45 percent in September, with further 2.3 percent rises in September 2009 and 2010. The three-year deal was recommended by the independent School Teachers Review Body.

While other unions such as the NASUWT and the Association of Teachers and Lecturers said they accepted the recommendation, the NUT said the rise was below the Retail Price Index inflation rate, and so amounted to a pay cut.

It argues that the pay award sapped morale, youngest teachers would be hardest hit, and it would deter graduates from applying to join the profession.

WHAT DOES THE GOVERNMENT SAY

The government has been trying to keep a tight lid on public sector spending and some unions said teachers had fared better than others.

Ministers say teachers’ pay has risen by 19 percent in real terms since 1997, without including salary increases that teachers receive by making their way up the pay scale.

So a newly qualified teacher who started work in 1997 on 14,280 pounds with a normal salary progression would now receive 34,281.

HOW MANY SCHOOLS ARE AFFECTED?

An LGA survey of 91 councils across England found that 1,896 schools would be shut with 2,006 partially closed out of 11,275 schools from the council areas surveyed. That meant that about 35 percent of schools would be affected by the action.

However there are regional variations with the survey finding out that a number of authorities in London had indicated that most of the schools in their areas would be shut.

In 2007, there were 25,018 schools in England with 8,149,180 children of school age.