Madrid/Gibraltar  - Spanish Foreign Minister Miguel Angel Moratinos was on Tuesday preparing to make a brief visit to Gibraltar, becoming the first Spanish cabinet minister to officially enter the disputed enclave since Britain took control of it in 1704.

Moratinos was to meet British Foreign Secretary David Miliband and Gibraltar Chief Minister Peter Caruana to discuss financial, maritime and judicial cooperation.

In an interview with the Spanish daily El Pais, Caruana described the visit as an "important political gesture" which would help to consolidate cooperation but meant "no progress or regression" in the thorny sovereignty question.

Spain's conservative opposition slammed the visit, with its spokesman Esteban Gonzalez Pons saying Spain might later be "ashamed" of Moratinos who "lowered the flag of a historic claim" of sovereignty over Gibraltar.

Moratinos was expected to avoid discussing Spain's claim of sovereignty over the enclave of 6.5 square kilometres, which was ceded to Britain by the 1713 Treaty of Utrecht.

The third ministerial meeting of the so-called tripartite forum came close to being cancelled after a row erupted between Gibraltar and Spain over territorial waters.

Spain angered Gibraltar by designating all waters around the enclave as Spanish under European Union environmental legislation. Madrid does not recognize the British claim that Gibraltar has 5 kilometres of territorial waters.

Caruana subsequently accused Spanish police of having increased incursions into Gibraltar waters. He advised vessels moving in Gibraltar waters to ignore orders from Spanish police and even to send distress flares if approached by them.

The dispute was smoothed over at the last minute, but it contributed to criticism from Spain's conservative opposition which said that Moratinos' visit amounted to a de-facto recognition of Gibraltar as a non-Spanish territory.

Moratinos was expected to meet with protests in Gibraltar, where the overwhelming majority of the 28,000 residents want to remain under British rule.

Madrid closed the Gibraltar border from 1969 and 1985, and continued hampering traffic with border checks until the tripartite process was launched in 2004.

It has improved phone and air connections, cross-border traffic and pension payments to Spaniards who worked in Gibraltar before the border was closed.

After the meeting in Gibraltar, Moratinos and Miliband were to discuss British-Spanish and international issues in the southern Spanish city of Jerez.(dpa)