Article 4U.K.
1.Activities relating to the representation of a client in legal proceedings or before public authorities shall be pursued in each host Member State under the conditions laid down for lawyers established in that State, with the exception of any conditions requiring residence, or registration with a professional organization, in that State.
2.A lawyer pursuing these activities shall observe the rules of professional conduct of the host Member State, without prejudice to his obligations in the Member State from which he comes.
3.When these activities are pursued in the United Kingdom, ‘rules of professional conduct of the host Member State’ means the rules of professional conduct applicable to solicitors, where such activities are not reserved for barristers and advocates. Otherwise the rules of professional conduct applicable to the latter shall apply. However, barristers from Ireland shall always be subject to the rules of professional conduct applicable in the United Kingdom to barristers and advocates.
When these activities are pursued in Ireland ‘rules of professional conduct of the host Member State’ means, in so far as they govern the oral presentation of a case in court, the rules of professional conduct applicable to barristers. In all other cases the rules of professional conduct applicable to solicitors shall apply. However, barristers and advocates from the United Kingdom shall always be subject to the rules of professional conduct applicable in Ireland to barristers.
4.A lawyer pursuing activities other than those referred to in paragraph 1 shall remain subject to the conditions and rules of professional conduct of the Member State from which he comes without prejudice to respect for the rules, whatever their source, which govern the profession in the host Member State, especially those concerning the incompatibility of the exercise of the activities of a lawyer with the exercise of other activities in that State, professional secrecy, relations with other lawyers, the prohibition on the same lawyer acting for parties with mutually conflicting interests, and publicity. The latter rules are applicable only if they are capable of being observed by a lawyer who is not established in the host Member State and to the extent to which their observance is objectively justified to ensure, in that State, the proper exercise of a lawyer's activities, the standing of the profession and respect for the rules concerning incompatibility.