The relationship between Portugal and the United Kingdom is usually referred to as the world’s oldest alliance. It goes back to the 12th century when English crusaders supported Portuguese independence from the Spanish kingdoms of Castile and Leon, and was later cemented in the Treaty of Windsor of 1386.

Since then, the Anglo-Portuguese alliance has been characterised by amiable reciprocity and it has served both countries well along the years. Both supported each other in key moments of history, such as the War of the Spanish Succession, Napoleonic Wars, World War I, and the Falklands War. More recently, based on a common transatlantic priority for international politics, both countries were part of the foundation of NATO. Also embedded in their natural and historical commercial spirit, they have worked together in the establishment of the European Free Trade Association (EFTA) in 1960, that both later abandoned to join the European Economic Community (ECC).

Close political and economic cooperation with the UK has always been core to Portuguese foreign policy, but their positions on European affairs evolved in separate ways, and the two now have very different places within the European Union.

Portugal is a member of the Eurozone, the Schengen area, and it sees its own economic and democratic modernisation much linked to the single market and political integration in the EU. In comparison, Britain didn’t adopt the single currency, opted out of the passport free area and always kept one foot out of the European project. Britain saw the European project as such a danger to its sovereignty and its national identity that it voted to leave the EU last year.

While the UK believes that there are alternatives to the European project and that more powers should be given back to national capitals, its southern ally is a big supporter of further integration, including, for example, completion of the single market in services, digital and energy. Lisbon has always been willing to listen and open to discuss British suggestions and, despite some divergences, has remained a key supporter of some of London’s proposed reforms such as less bureaucracy and regulatory red-tape, and more free trade with like-minded dynamic economies around the world.

However, when Britain’s policy proposals touch upon structural issues and have the potential to jeopardise the European project, there are no special relationships for Portugal. This is why when David Cameron visited Portugal in 2015 to gather support for a package of proposals that included limits to free movement of people and welfare restrictions for EU migrants, he did not get the reaction he wanted from Britain’s old friend.

The response was not only based on European interests, but also on specific Portuguese ones. Approximately 200,000 Portuguese nationals live and work in the UK and would have eventually been affected by the measures. The Prime-Minister António Costa even told his Parliament last year that Portugal “more than anyone” wants to keep Britain in the EU, but his government was not willing to compromise more.

He did not compromise and he did not keep the UK in the EU. Now, Costa will be looking into the best deal possible to keep the historic bond alive. Today, approximately 80,000 British citizens live and work in Portugal, and around 2 million more visit the country every year. In addition to this, the UK is one of Portugal’s largest export markets with approximately €3 billion worth of goods per year, also using Portugal as a gateway to a market of 250 million people in the Lusophone countries. Therefore, depending on the arrangement, Brexit may have serious implications for Portuguese citizens, businesses, and consumers. The UK must seize on her present and historic bilateral links to help her through this difficult time. A positive outcome can only be achieved with goodwill and compromise, and Portugal, as Britain’s oldest ally, can be a key player and a moderate voice in negotiations.

Written by Daniela Dias Rodrigues