Trade unions have no autonomous voice. They can only be the transmission belt of globalisation to the working people rather than filling their earlier role of being the transmission belt of Party agendas to the workers. Under communism their function was very similar - that of disciplining workers and ensuring flexibility in the use of labour and low money wages, as the Party agenda required. The only difference is that under communism there was over-full employment (not by design but as a by-product of excess demand for under-priced goods). Under capitalism any refusal to transmit globalisation to the workforce results in additional unemployment - which is an alternative mechanism for disciplining workers.
Globalisation, or free trade as we used to call it, raises productivity much of which is enjoyed by us all through lower prices. But we cannot have high wages, high employment and low prices resulting from globalisation.
Protectionism offers higher employment levels at higher wages with higher prices and lower productivity. If the trade unions under capitalism favour protecting members' employment and high wages then they must press for protectionism. And a ban on immigration and on capital outflows.
What an agenda. What is the point of trade unions?