Spanish police plan to remove voters from polling stations for Catalonia’s independence referendum, an informed government source says.

The official made the remark on Saturday, without providing further details as to how the police would remove people, Reuters reported.

The source noted that volunteers staffing polling stations in Sunday's banned referendum would be liable for fines of up to 300,000 euros ($354,360).

According to the Spanish government, police have so far shut down 1,300 of 2,315 schools designated as voting stations in Catalonia.

The measure has faced public resistance, as volunteers and local residents reportedly occupied the building of a polling station in central Barcelona and set up camps around another.

The president of the Catalan National Assembly, Jordi Sanchez, called on Spanish police forces to “appeal to their conscience” and let the Catalan people “express themselves in freedom."

Catalan pro-independence activists hold a gathering in Barcelona on September 29, 2017. (Photo by AFP)

The referendum, which is planned for Sunday, is considered by the central government a violation of Spain’s constitution.

In order to halt the vote, Madrid has increased pressure on Catalan officials over the past week. It has deployed thousands of extra police from across the country to Catalonia to stop the vote.

On September 20, Spain’s military police also raided Catalan government offices, during which at least 14 junior officials and associates were arrested and almost 10 million ballot papers were seized.

The websites informing Catalans about the election have been shut down. Google has also deleted a smartphone application publicized by regional Catalan officials aimed at directing voters to their nearest polling stations.

The regional government has, however, vowed that the poll will go ahead on Sunday despite Madrid’s crackdown.

Catalonia’s head of foreign affairs, Raul Romeva, has urged the European Union to take steps over the issue.

“Democracy in Spain decays day by day. Spain is a member of the EU, so the European Commission can no longer argue that it is an internal affair,” Romeva said.

Catalonia, one of Spain’s 17 autonomous regions, held a symbolic referendum back in November 2014, during which more than 80 percent of participants -- 2.3 million -- voted for independence for the region, according to Catalan officials.