The only royal who actually can't say anything political is the monarch. The rest are able to do so but generally don't. Same as those royals who are also commoners are eligible to vote and/or stand for election to the House of Commons but again they don't. The royals who are also commoners by the way (Camilla, Kate, Harry, Beatrice, Eugenie, Sophie, Anne, Birgitte, Katherine, Michael, Marie-Christine and Alexandra). The others (Philip, Charles, William, Andrew, Edward, Richard and Edward) are peers of the realm and until 1999 were eligible to sit in the House of Lords with only Richard and the elder Edward not eligible to take up a seat in the newly reformed Lords - they chose not to do so but could have done so - as Earl Snowdon did for instance).