Madrid was prepared to let the vote go ahead as long as it was only an exercise in "freedom of expression", Spain's new justice minister Rafael Catalá said.
"If the Catalan government does not promote acts towards an unauthorized consultation, it does not appear necessary to turn to the Constitutional Court or other judges and tribunals, since there will the law will not have been broken," he said.
"In a democratic society like Spain the constitutional rules permit many daily popular movements to collect signatures to find out people’s opinions," Catalá was quoted as saying by Spain's El País newspaper.
"What we argue is that a government cannot promote a consultation that is not line with the Constitution. But nobody is going to stop people from exercising freedom of expression."
The comments mark an attempt to lower the tone of an often heated debate between Madrid and Catalonia over the vote and promote an atmosphere of calm in the lead-up to the long-anticipated poll.
Catalá's words also came just hours after Spain's Supreme Court rejected an appeal by the Catalan government against the Constitutional Court’s suspension of the vote on Sunday — the latest sally in a long-running legal battle over the Catalan independence vote.
The latter court responded to a challenge against Mas’s watered-down consultation made by the Spanish government by declaring a suspension on the proceedings until it could rule on whether the vote was constitutional.
The Spanish government argues that Sunday’s vote is a referendum albeit in the guise of a participatory poll and says that only the state can call such polls. Mas has denied that his government is running the vote on Sunday, for which thousands of volunteers have registered to oversee proceedings.
However, hard line pro-independence groups are pushing for the government to be involved in the poll until the very final stages.
Mas announced the symbolic vote after Spain's Constitutional Court suspended earlier plans for a non-binding referendum on secession in September. Catalan officials argue the symbolic vote, which they call a "citizen participation process", is different from the official referendum because it has a less direct government role and doesn't contravene Spain's constitution.