The agreement has been signed between the unions and the Mace/Dragados joint venture building the new Euston Station.
It secures the right of trade union representatives to visit the project’s inductions as well as welfare facilities to talk to all the workers on the site during their breaks, in order to deal with any concerns or worries that they may have.
The joint unions are now working to ensure that similar agreements are signed for all areas of the HS2 project.
Unite national officer Jerry Swain said: “This is a landmark agreement and establishes the path for harmonious industrial relations on HS2.
“The HS2 project is the largest construction project in Europe, in order for it to be delivered on time and on budget it is essential that workers are treated with respect.
“In order for that to be achieved it is essential that recognised unions are able to freely engage with our members and other workers on site, get them organised, understand their concerns and resolve their problems.”
Charlotte Childs, national officer, GMB said: “This is a great agreement that sets the tone for trade union engagement on the HS2 project.
“Our members will be instrumental in the successful delivery of the Euston Station project and we are pleased that Mace/Dragados have embraced the joint working seen within this agreement to get a better deal for all involved.
“Projects that have trade union membership lead to a safer, valued and effective workforce and we are pleased to be working with Mace/Dragados to deliver that.’’