I hope I can assist you with your query.
In order to be eligible for British citizenship, you need to have lived in the UK for at least 5 years, which I understand is the case since you have been living in the UK since 15th December 2005 as the spouse of a Portuguese citizen.
The other requirements are that:
You can find out more about naturalisation here:
The form to use is Form AN which you can download along with the guidance notes:
I hope my answer was useful to you. If so, I would be grateful if you could accept my answer.
I thank you in advance.
DISCLAIMER: Answers from Experts on JustAnswer are not substitutes for the advice of an attorney. JustAnswer is a public forum and questions and responses are not private or confidential or protected by the attorney-client privilege. The Expert above is not your attorney, and the response above is not legal advice. You should not read this response to propose specific action or address specific circumstances, but only to give you a sense of general principles of law that might affect the situation you describe. Application of these general principles to particular circumstances must be done by a lawyer who has spoken with you in confidence, learned all relevant information, and explored various options. Before acting on these general principles, you should hire a lawyer licensed to practice law in the jurisdiction to which your question pertains.
The responses above are from individual Experts, not JustAnswer. The site and services are provided “as is”. To view the verified credential of an Expert, click on the “Verified” symbol in the Expert’s profile. This site is not for emergency questions which should be directed immediately by telephone or in-person to qualified professionals. Please carefully read the Terms of Service (last updated February 8, 2012).