Thousands of Gibraltarians celebrated 300 years of British rule by forming a human chain around the Rock on Wednesday while Spain fumed over the presence of a British minister.
Some 12,000 people, dressed in Gibraltar's colours of red and white and waving British "Union Jack" flags, linked hands, encircling the Rock in a symbol of unity.
Wednesday is the highpoint of year-long celebrations marking the 300th anniversary of Gibraltar's occupation by an Anglo-Dutch force in 1704.
The celebrations have raised tension between Britain and Spain over the tiny British colony on the Spanish southern coast over which Madrid seeks to recover sovereignty.
Spain has protested to Britain over the presence of Defence Secretary Geoff Hoon at Wednesday's celebrations, calling it the latest of a series of "unfriendly gestures" that included a recent trip to Gibraltar by Britain's Princess Anne and a visit by British nuclear submarine HMS Tireless.
Spanish Prime Minister Jose Luis Rodriguez Zapatero joined the controversy on Wednesday. "Neither the government nor the immense majority of Spanish society thinks what we have seen is appropriate," he said, in what Spanish media said was a reference to London's conduct.
"But, I insist, we have a 300-year-old problem and we have to tackle it with care, calm and with dialogue," he told reporters as he arrived in the island of Menorca for a holiday.
Gibraltar Chief Minister Peter Caruana insisted Gibraltar had a perfect right to celebrate its history.