The Foreign Office has summoned the Spanish ambassador after a "serious Gibraltar incursion", Reuters reports.
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The young royal says he was reluctant to take on the responsibilities of his title, but loyalty to the Queen helped him "work out a role".
A rather cloudy morning will clear to sunny intervals and showers this afternoon.
Meng Meng and Jiao Qing arrive in their new home after being loaned to Berlin Zoo for 15 years as "diplomatic envoys" from China.