A case will be made for CalMac services to remain in public ownership.
A leader of the Transport Salaried Staff's Association (TSS) will be visiting staff in CalMac's port offices in Uig and Armadale on Wednesday 8 August.
Manuel will be visiting Skye as part of a tour of the Hebrides.
Manuel Cortes stated: "There must be no future tendering of CalMac services. Last time around over £8million pounds of taxpayer's money was wasted on the franchise process."
Manuel added: "It's no exaggeration to say that CalMac Ferries are vital for the survival of ordinary working people in the Scottish Islands. They don't only allow families to stay in touch, they bring food and supplies and carry the Islands' exports to the mainland – they are the very definition of a lifeline service.
"I'm extremely proud of the part our members in CalMac, play and that's why I'm looking really forward to visiting some of them in August."
Above: Manuel in Largs.