Scotland's schools are facing the first strike in almost a quarter of a century.Members of the largest teaching union, the Educational Institute of Scotland (EIS), have voted overwhelmingly for a day of action.It is likely to take place on 30 November.Union leaders said the patience of teachers had been exhausted by a pay freeze, budget cuts and proposed changes to pensions.The EIS said more than 82% of members who voted were in favour of strike action. Turnout was 54%.The planned action is expected to be rubber stamped by the union's executive meeting and is expected to take place at the end of the month when many other public sector unions are also taking part in a day of action over pensions.Union leaders said concessions mooted by the UK government earlier this week were not concrete enough as yet to prevent industrial action.This will be the first national strike by EIS members in almost 25 years.The union's general secretary, Ronnie Smith said: "This 82% vote for strike action is the strongest indication so far that the patience of teachers and lecturers has been exhausted."Faced with a wide ranging attack on their pensions, on top of a two-year pay freeze, rampant inflation and education budget cuts, our members are signalling that 'enough is enough'."Teachers and lecturers are highly committed professionals who do not decide lightly to strike - it is more than two decades since the last national strike action. However, the pensions 'triple whammy' of being compelled to pay more, work longer and get less has to be challenged."Mr Smith said teachers wanted to see further progress from the government on pensions and "concrete proposals" specific to schemes in Scotland.He said the EIS would continue to work to secure a fair settlement for members.Members of the Association of Headteachers and Deputes in Scotland (AHDS) have also voted in favour of a day's strike but leaders have delayed naming a day to allow time to consider the government's revised proposals on pensions.