"We weren't expecting any movement really. We were determined to have our previous agreement recognised and completely willing to withdraw our labour.
"But when we found out we did a massive U-turn really, from resentment and determination to real relief and everyone is happy to be at work again," he said.
The new agreement will see the full implementation of the independent pay review commissioned by St John. It ensures no staff member will earn less than they would have from a previous agreement to implement 25 per cent penal rates for nights and weekends for a transitional period.
The St John Board has approved the executive team's request to increase the ambulance service operating deficit by a further $1 million to enable the settlement.
Concerns raised during bargaining about pay progression for existing call handlers and dispatchers have also been resolved as part of the offer, the statement said.
First Union transport, logistics and manufacturing secretary Jared Abbott described the settlement as "an excellent outcome" for all staff.
"This is a fair offer that will see a number of staff receive significant pay adjustments to reflect their skills while ensuring that everyone benefits.
"The settlement is the first step in rebuilding the relationship between the parties and will allow staff to refocus on their key priority of providing a safe and effective ambulance service."
A St John spokesperson said it was pleased to have been able to avoid strike action for the public while continuing constructive discussions with First Union colleagues to reach an agreement that suited all parties.
"We are very pleased to reward our people with the full implementation of the independent pay review. This is a historic and significant pay correction for our people."