What law governs the use of the Portcullis by both Houses and what course of action should be taken if it is used illegally
The principal emblem of the House is the Crowned Portcullis. It is a royal badge and its use by the House has been formally authorised by licence granted by Her Majesty the Queen. The designs and symbols of the House should not be used for purposes to which such authentication is inappropriate, or where there is a risk that their use might wrongly be regarded, or represented, as having the authority of the House.
The House symbol is primarily used to authenticate communications from Members.
Usage of the Crowned Portcullis which falls, or appears to fall, outside the above purposes may be referred to the Speaker, who may ask the appropriate House authorities to look into the matter and where appropriate inform the person or organisation concerned about the rules governing its use.
Alleged breaches by Members of Parliament of the rules relating to the use of the Crowned Portcullis may be investigated by the Parliamentary Commissioner for Standards.