Spanish Prime Minister Mariano Rajoy has warned that any declaration of independence by Catalonia will have no effect, adding that he is not ruling out suspending the region's autonomy. <br/><br/>In an interview with El Pais newspaper published today, Mr Rajoy also rejected any mediation to resolve the crisis. He said the government will ensure that any declaration of independence will lead to nothing. The prime minister also said he planned to keep extra police deployed to Catalonia until the crisis was over.<br/> <br/>Earlier, thousands of people rallied across the country for Spanish unity. The demonstrations were in response to last Sunday's disputed referendum on Catalan independence. The final results from the wealthy north-eastern region showed 90 percent of the 2.3 million people who voted backed independence. The turnout was 43 percent.