Scottish members of the NASUWT condemned the deal on teachers' pay and conditions, proposed by council leaders and the Scottish Government, at the union's annual UK conference in Glasgow last weekend.
It was "a full-scale assault on each teacher in Scotland, regardless of age, gender or sector", said Scottish executive council member Linda Gray.
She attacked the EIS union for changing its stance and now recommending support, adding that teachers needed security.
Committee member Victor Topping called for teachers' conditions of service to be made statutory as trust in Cosla (the local authority umbrella group), the Scottish Government and the Scottish Negotiating Committee for Teachers had been lost.
The direst warning came from their colleague Musaffer Hussain, who told the conference: "We are only a stone's throw from being like the Upper Clyde shipbuilders. The spawn of Thatcher say we are `in it together' and Bill and Ben have been reincarnated to run the country."
NASUWT general secretary Chris Keates said that while Scotland had previously led the way in the UK for teachers' pay and conditions and training, it was now the region being attacked first.
The conference also heard claims that newly-qualified teachers stood to lose almost pound;3,000 a year, due to cuts to the public sector by the UK Government.
A first-year teacher in England earned pound;21,588, but after a 1 per cent rise in national insurance, rising inflation and increased pension contributions, new entrants would lose pound;2,924 a year, claimed the union.
Ms Keates compared new teachers' pay to the pound;40,000 starting salary of someone on the graduate development programme with the Aldi supermarket chain, citing High Fliers research.
"Why would someone choose teaching when they can earn double by working in a supermarket?" she said.