Residents of rocky colony fly the flag to demonstrate their allegiance to Britain

The first Spanish minister to visit Gibraltar for 300 years crossed the border this afternoon, skipping the normal traffic jams and being greeted by union flags hanging from windows and balconies.

Foreign minister, Miguel Angel Moratinos, is making his historic visit to the Rock under the terms of a three-way agreement with Britain, Gibraltar and Spain that has done much to ease centuries of mutual antagonism over the tiny colony.

He is meeting Britain’s foreign secretary, David Miliband, and Gibraltar’s chief minister, Peter Caruana, to sign agreements covering everything from police co-operation to the environment.

Uniformed Gibraltarian bobbies greeted Moratinos’ car as it skipped the queues that normally form at the border and drove straight on to the Rock.

Gibraltarians dusted off their union flags and hung them out to remind Moratinos where their loyalties lie.

Although recent agreements signed under the three-way pact have helped sort out many historic gripes, Spain still claims sovereignty over the two-and-a quarter square miles of rocky outcrop.

That sovereignty was signed away in the Treaty of Utrecht in 1713 but Spain claims that, under United Nations decolonisation rules, Gibraltar should have been handed back long ago.

Moratinos and his hosts were due to ride the cable car to offices high up the 1,300ft rock that dominates Gibraltar, where they were to hold their meeting.

A recent spat over the maritime frontiers between Gibraltar and Spain had put today’s meeting in danger.

Caruana recently called on Gibraltar boats to fire off distress flares to call for help if they were stopped by Spain’s civil guard patrol boats while approaching the Rock’s harbour.

Spain’s opposition conservative People’s Party (PP) has called Moratinos a “traitor” and claims the visit is an “insult to the dignity of Spain”.

“This is one more backward step towards renouncing the battle for Spanish sovereignty,” said the PP’s secretary general in the southern region of Andalucía, Antonio Sanz.

The opposition Gibraltar Socialist Labour Party condemned the visit, saying it should not have been allowed while Spain was claiming sovereignty over disputed waters. “The fact that Mr Moratinos is coming is, for us at least, an opportunity to show him just how British Gibraltar is and will stay,” said party spokesman Fabian Picardo. “We certainly won’t have our noses rubbed into Spain’s latest affront to the sovereignty of our waters.”