That depends! It isn't "easy" to get a loan from any reputable lender these days unless you satisfy fairly strict creditworthiness criteria.
For secured lending, they look for security usually a suitable property in either the UK or Spain. The property should have no more than one secured charge (mortgage) already on it. Your proposed loan will form the basis of a second charge (unless it is already mortgage free.)
The total amount of the combined charges (the existing mortgage and the proposed loan,) should not exceed 60% of the value of the property.
The loan proposer (you) and or your guarantors, should be able to satisfy affordability and credit criteria in accordance with the banks normal lending policies.
The response time will vary depending on the result of those checks and the criteria being met. An "in principle" decision should be quite rapid.