Britain has accused Spain of violating its sovereignty by allowing a Spanish coastguard patrol boat and helicopter to enter disputed waters and airspace off Gibraltar while in pursuit of suspected drug traffickers.
In the incident on Sunday, two suspected smugglers were arrested, but one escaped.
Britain, which has run Gibraltar since 1713, said in a statement that cooperation between Britain and Spain was vital to “curtail drug trafficking, people trafficking and terrorism in the Strait of Gibraltar.”
But it called Sunday’s incursion “unlawful and unacceptable” and said it was dangerous when a Spanish helicopter flew over the Sandy Bay area without warning British authorities.
Spain considers Gibraltar to be Spanish territory and wants to reclaim it, and didn’t see the coastguards’ actions as a violation of sovereignty, an unnamed Spanish foreign ministry official told El País newspaper.
Gibraltar’s Chief Minister Fabian Picardo said the Spanish actions “ultimately resulted in the escape of a criminal that citizens on both sides of the frontier would have liked to have seen arrested and imprisoned for his drug trafficking.”
If the Spanish police had warned Gibraltar authorities, they could have deployed maritime and ground resources to help capture the smugglers, he said.
Tension in the long-standing territorial dispute has escalated in recent years. Spain, for example, complained in 2013 that the construction of an underwater reef in Gibraltar would damage its fishing industry.
In response, Madrid tightened border checks for travelers to Gibraltar, provoking a diplomatic rift.
At the time, British Prime Minister David Cameron said the new border checks were politically motivated and violated the European Union principle of free movement. The European Commission, however, concluded the additional Spanish border controls were lawful.