Scottish teaching unions have warned that the St Andrew's Day strike is "extremely likely" to be the start of ongoing industrial action, as the pensions dispute shows no sign of resolution.
As thousands of teachers prepared to take to the streets in the first industrial action to hit Scotland's schools in decades, union leaders were already talking of possible further walkouts.
Speaking ahead of protest marches across the country, Jim Docherty, depute secretary of the Scottish Secondary Teachers' Association, said: "Given that the full proposal will not come into effect until 2015, there is an extreme likelihood that public sector pensions will still be an issue in the run-up to the next general election."
Secondary heads' body School Leaders Scotland, which did not take part in Wednesday's strike action, warned that it would ballot its members on future walkouts if talks failed.
Ken Cunningham, SLS General Secretary, said: "The fact that we are not striking at the moment doesn't mean we're happy with what the (UK) government is doing."
Meanwhile, Scotland's largest teaching union, the EIS, accused the UK Government of fuelling the dispute after it repeatedly threatened to take the current offer off the table if strike action went ahead.
Assistant secretary Drew Morrice said the EIS and other unions would consider further action at a meeting planned for next month.
General secretary Ronnie Smith dismissed the idea that unions were alienating the wider public by striking. "We have been encouraged by strong support from parents and the wider public for our campaign," he said. "Parents understand very well the pressures associated with the increasing cost of living at a time of pay restraint and pay cuts."
For teachers the average pension was about pound;10,000 a year, he said, "contrary to the anti-public sector propaganda that has been circulating in recent weeks".