Fine Gael and Labour have pledged to undertake a complete review of the decentralisation programme if they are in Government after the general election.
Fine Gael deputy leader Richard Bruton and Labour finance spokeswoman Joan Burton were among several TDs who last night promised their support to Siptu in its campaign against the Government's decentralisation programme.
Politicians from all parties were invited to address the Siptu meeting in Liberty Hall, Dublin. No members of Government parties attended.
Siptu is the largest union representing employees of semi-State agencies with members in organisations such as Enterprise Ireland and the Arts Council.
The union said decentralisation is not viable for these workers because there is no mechanism for transferring between agencies, so all workers would have to agree to go to the same location.
Of almost 1,600 workers only 56 have applied for decentralisation.
In announcing the decentralisation programme without consultation the Government had abused its powers and "thrown aside the system of checks and balances", Mr Bruton said.
No strategic planning had taken place and no business case had been made for decentralisation he said, and it was "put together purely as a political stroke". The Government had made "serious promises" and commitments to people in various parts of the country that they would be host to decentralised jobs, but these promises were unworkable when more than 95 per cent of employees were against transferring, he said.
Decentralisation was "a shambles" and a complete overhaul of the programme was needed, Ms Bruton said. "Labour in government will certainly ensure that the plan goes back to the drawing board".
The recent publication of the National Development Plan which reinstated the concept of developing particular regional gateways and hubs without reference to the decentralisation locations, meant the Government had already abandoned decentralisation but "is unwilling to say this so close to a general election" she added.
Socialist TD Joe Higgins said he had been a strong advocate of decentralisation but the bullying tactics used by the Government to force workers to move were crude and unjust.
"We are not living in a Stalinist gulag," he said.
The Green Party's Dan Boyle said that if his party was in Government the decentralisation programme would not continue in its present form.
Independent TD Finian McGrath said the independent TDs in the Dáil would support Siptu.