PARK College teachers took strike action on Tuesday over plans to move away from nationally-agreed sixth-form teachers' contracts.
There was a solid turnout of National Union of Teachers members outside the college, according to East Sussex NUT secretary Dave Brinson.
Pickets reported that despite 'management bravado' saying the college would be open as normal, only a handful of classes were running and students said they had been told to go to the library or to go home.
Mr Brinson said, "This strike is not about teachers demanding more money. My members simply want to preserve the conditions they already have and are not willing to see future, younger colleagues employed on inferior contracts.
"We need the most educated and qualified young people possible, more so in the current economic climate than ever.
"Attacking the pay and conditions of skilled and dedicated teachers is not the way to achieve this."
Around 30 Park College staff mounted a protest and handed out literature to the public.
"We are really heartened by the support we have received from the people of Eastbourne today," said Mr Brinson.
"Most parents are horrified at a system where the professionals who teach their children A-levels will be paid less than the teachers who took them through school."
Lib Dem campaigner Stephen Lloyd told the Herald he was disappointed the two sides couldn't resolve the issue without strike action.
"However, I do want to make it very clear that I support the teachers at Park College on this issue," he said.
"We were promised when Sussex Downs took over Park College that A-level academic standards would not drop.
"Since then, a number of parents and teachers have contacted me expressing their concerns.
"It is vital, therefore, that no cuts are made under the smokescreen of the economic downturn."
A Park College spokesperson said, "The NUT action was extremely disappointing as it was not in the best interests of the students.
"However, Park College remained open on March 24 and there was the minimum possible disruption to classes, as appropriate learning arrangements were made for students.
"For equality and pay legislation reasons, all new lecturers and teachers joining Sussex Downs College must be appointed on the same terms and conditions, regardless of which area of the college they work in.
"Arrangements have been made to protect the contracts of Park College colleagues who joined Sussex Downs following the merger in 2003.
"The Sussex Downs College Corporation is convinced that these arrangements are both fair and reasonable.
"Park College's success rates have significantly improved since the merger in 2003 and were one of the reasons we were awarded Beacon College status in 2008.
"Park College's latest A-level results were some of the best ever.
"The college will be contacting Mr Lloyd so that a meeting can be arranged to give him details of Park College's recent successes and to discuss any issues he would like to raise.
"We are, frankly, disappointed that he did not raise these issues directly with us in advance of making his statement."