Translation:We would protest for safer contracts.
I assume it means contracts that include clauses defining safe working conditions for the workers. The English sentence makes no sense anyway and should be something like : We would lobby for safer contracts. If you want to use the word 'protest' you could say: We would protest AGAINST insecure contracts. This could have a different meaning from the safety aspect. To me, an insecure contract is one that does not provide a good level of certainty for both parties from a contractual point of view.