The issue of Catalan independence is once again a hot topic in Spain, with pro-independence groups threatening to declare unilateral independence if they win at the upcoming regional election on September 27.
However, Cameron warned that this would automatically result in Catalonia being expelled from the EU, from which they would need to reapply.
"Just like the UK, Spain is a great country with a long and proud history, and if I had a message, it would be the same as the one in the UK, that we are better off together," Cameron said in Madrid, backing the calls of Spanish Prime Minister Mariano Rajoy, who is strongly against Catalan independence.
"If one part of a state secedes, it’s no longer part of the European Union and has to take its place at the back of the line behind those other countries applying to become members of the European Union."
The threat of separatism is a phenomenon common to both the UK and Spain in recent times, with Scotland last year voting to remain part of the kingdom, despite significant support for independence from various groups.
Cameron’s comments come amid the PM’s visit to Spain to gather support for the UK’s push to introduce EU reforms.
It’s thought that along with quashing similar independence movements in Scotland, Cameron’s support for a united Spain would be looked upon favorably by Madrid, who may be more likely to support Britain’s EU reforms bid.
On top of independence movements, the two leaders also addressed the current refugee crisis enveloping Europe.
Spain and the UK have remained opposed to German proposals to accept minimum quotas of refugees. However both countries have announced in recent days that they will increase their intake of people from war-torn countries in order to alleviate the pressure on other EU countries.