In 2022, a milestone was reached in post-Brexit EU-UK relations, the creation of the Parliamentary Partnership Assembly (PPA). The PPA, which meets twice per year, was envisaged by the Trade and Cooperation Agreement (TCA), the treaty that set the terms of the new EU-UK relationship following the UK withdrawal. It is a joint body made up of 35 members of the European Parliament and 35 members of the UK Parliament (21 from the House of Commons, 14 from the House of Lords).

Part of the purpose of the PPA is to be a site of parliamentary diplomacy, a talking shop in which parliamentarians from the UK and the EU can meet together periodically to discuss matters of common concern. In this regard the PPA has a role in rebuilding relationships that have been badly damaged as a result of the bad blood engendered by Brexit and its aftermath.

However, the PPA arguably has a more specific and vital function: to act as a joint parliamentary body to scrutinize the Partnership Council, the institution that governs the implementation and operation of the TCA. In addition, it also acts informally to oversee the Joint Committee for the implementation of the Withdrawal Agreement, including the Northern Ireland protocol, even though this is formally outside the scope of its powers.

This paper will analyse the conception, creation and early history of the PPA, showing how it has navigated its twin roles of talking shop and oversight body. Regarding the latter, it is apparent that this job is very difficult when EU-UK relations are fractious. After all, if the Partnership Council is gridlocked, there are no joint decisions for the PPA to scrutinize. The functioning of the PPA improved as when the state of EU-UK relations improved in late 2022 and early 2023.

Following the UK's withdrawal from the EU there has been an extended period of contestation over the direction and content of future relations between the two. However, with the notable and significant exception of the Withdrawal Agreement's Protocol on Ireland/Northern Ireland, there has been much less disagreement about the architecture within which those relations will unfurl. The Trade & Cooperation Agreement provides a flexible framework for both current and future areas of cooperation and collaboration, while both parties have also started to settle on their internal management and coordination structures, regularising new patterns of involvement of domestic political, economic and social agents. This paper provides an interim overview of this constellation of arrangements, seeking to identify the key gatekeepers and veto players within the systems who are likely to play significant roles in the future development of relations. The paper highlights the different extent to which the Protocol question has been compartmentalised in organisational and political terms and offers tentative conclusions about the resilience and adaptability of the Agreement, especially in the face of continuing tensions over the Protocol and its operation.

Since it left the EU, the UK has signed multiple bilateral declarations and statements with EU member states. Although they have received less attention than the UK’s renegotiated trade deals, they form an important element of the UK’s post-Brexit diplomatic strategy and are featured in the UK government’s Integrated Review Refresh. This paper offers a provisional examination of these agreements. It looks at their interaction with the Withdrawal Agreement and the Trade and Cooperation Agreement, assesses their significance, and discusses what they signal about the opportunities available to the UK for forging bilateral ties as a third country.

The analysis is based on the contents of the joint bilateral agreements, and what they reveal about post-Brexit diplomatic opportunities for the UK and their limits. One the hand, these confirm the crucial role of the UK in defence and security in Europe and the UK’s position as a strategic ally. On the other, they highlight that opportunities for cooperation in many areas are necessarily delimitated by the existing UK-EU framework. As such, they underscore continuing solidarity among EU member states in the face of the UK’s withdrawal from the EU and how the possibilities for the UK to arrive at individual understandings with its European neighbours are defined by EU competencies, and structured by the Withdrawal Agreement and, particularly, the Trade and Cooperation Agreement.