1. Dear *****o, there is only one way to get citizenship and that is that you apply based on five years continuous residence or based on your marriage to a UK citizen. For both it is five years and for both there is the life in the UK test and an English language requirement. There is no way to bargain around these requirements. You simply have to fulfill them or you don't get citizenship.
2. The first step you need to take is to obtain a Permanent residence card. You will need to hold this Permanent Residence card for a period of one year or else show by some other means that you have been living in the UK for the last five years so you can automatically apply for citizenship. here is a link to the application forms for a Permanent Residence card https://www.gov.uk/government/publications/apply-for-a-document-certifying-permanent-residence-or-permanent-residence-card-form-eea-pr
3. However, you have a cast iron case for citizenship. This ultimately is the only answer to the UK leaving the EU. Otherwise you will have to continuously apply for a visa. Be aware that you can hold joint UK and Portuguese citizenship at the same time.
4. Please Rate the answer as unless you Rate the answer your Expert will receive no payment for answering your question.