1. ITV Report

UK considers 'unprecedented step' of legal action against Spain over Gibraltar

Aerial view of Gibraltar. Photo: Matt Morton/PA Wire

Britain is considering the "unprecedented step" of legal action against Spain after they continued with additional checks at the border of Gibraltar, Downing Street said.

The Prime Minister threatened to take Spain to the European Court after they continued with the extra controls.

Downing Street described the country's behaviour as "politically motivated and totally disproportionate" while Spain threatened to take Britain to the United Nations as diplomatic relations between the two deteriorate.

As planned, the Royal Navy headed south today with one ship calling in at Gibraltar.

The helicopter carrier HMS Illustrious left Portsmouth Naval Base, Hampshire, and will join the navy flagship HMS Bulwark, which has sailed from Devonport for the Cougar '13 operation.

HMS Illustrious sets sail from Portsmouth today. Credit: Royal Navy

Also sailing tomorrow will be HMS Westminster, a type 23 frigate, which will visit Gibraltar en route.

A Downing Street spokesman said the Prime Minister was "disappointed" by Spain's refusal to remove the border checks over the weekend.

Clearly the Prime Minister is disappointed by the failure of Spain to remove the additional border checks this weekend.

We are now considering what legal action is open to us.

This would be an unprecedented step so we want to consider it carefully before a making a decision to pursue.

– Downing Street spokesman

The move comes after a bitter argument over the the construction of an artificial reef by the Gibraltarian authorities, which Spain claims will destroy fishing in the area.

Madrid responded by beefing up border controls - leading to lengthy queues - and suggesting a possible €50 (£43.30) fee could be imposed on every vehicle entering or leaving the British territory through the border with Spain.

Downing Street said that any possible legal action would be done through Europe.