Lisbon Agreement, 1980

The Lisbon Agreement was the first of a series of agreements between the British and Spanish Governments intended to resolve their existing differences over Gibraltar.

The 1969 Constitution made it clear that the British would not impose a solution on the Gibraltarians and acknowledged their right to self-determination in their own political future. Franco continued to insist that Gibraltar was territorially integral to Spain and "in a fit of diplomatic pique" ordered the closure of the border in 1969. For the next 16 years Gibraltar was reliant on an air-link with Britain for formal access to the outside world.

The closure of the border hardened attitudes in Gibraltar both towards Franco and Spain more generally.

It is also ironic that the actions taken by Francisco Franco and Spain completely destroyed any potential for winning over the population and gaining support in either Britain or Gibraltar for transfer of sovereignty to Spain...This natural tendency of the two populations to interact demonstrated the artificial division that had been created and continued to exist so long as Britain retained possession of Gibraltar. Instead, he demanded the immediate return of Gibraltar, initiated a newspaper campaign in which the entire population was characterised as criminals and individuals of dubious moral character, and imposed border restrictions that caused real hardship on the inhabitants.

A diplomatic stalemate persisted until, following the death of Franco, the Thatcher government initiated a new political process that resulted in the . This was a joint statement by the Spanish Foreign Minister Marcelino Oreja and the British Foreign Secretary Lord Carrington signed in Lisbon on April 10, 1980. The preamble stated:

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