The lifting of the arch was due to start yesterday afternoon after a successful test last weekend.
A project insider said there was widespread discontent among workers over what they said amounted to a wage cut.
The insider said: "The canteen meeting was held on Wednesday morning as workers stood to lose about £300 a week and everybody felt it was time to make a stand."
The insider said that the workers eventually negotiated a compromise deal with the subcontractors.
A Multiplex spokesperson said that all of the subcontractors working on the project had been told four months ago about the site closures during the lifting process.
The spokesperson said that the site had to be cleared during the lifting of the arch for safety reasons. He said the issues raised at the meeting had been resolved quickly and work had resumed in two hours.
The next stage in lifting the arch will take place over the weekend when it will be raised to a gradient of 30°. Over the next four to six weeks the arch will be lifted to a 112° angle, at which point it will be locked off.
Building revealed last week that the unions had objected to the fact that Multiplex had taken control of the safety induction training on the project and that it was stopping them recruiting members. However, the issue was resolved and the unions will now resume its induction sessions. Multiplex said last last week that the sessions would be carried out by both unions and contractor using a rota system.