A UK Royal Air Force aircraft carrying British Foreign Secretary Philip Hammond was banned from flying through Spanish airspace on its way to Gibraltar, British media have revealed.

The incident took place on Wednesday, when the British foreign secretary was  heading to Gibraltar to meet residents to ensure they don’t support exit of the country from the EU at the June 23 referendum, the Sunday Express reports.

Spanish authorities were aware of Hammond being on board the plane, but issued the ban anyway, forcing RAF pilots to change course and fly via Portugal, Russia Today reported on Sunday.

While visiting Gibraltar, Hammond warned that if Gibraltarians do support Brexit, London would not be able to protect their interests.

Madrid also warned Gibraltar residents against voting for exiting the EU, promising to establish a blockade of the territory similar to the one enacted by Spanish Dictator General Franco in 1969 which lasted until 1982, well passed the general’s death.

British military aircrafts have been banned from flying through Spanish airspace if their final destination is Gibraltar since 1989. Wednesday’s reported demarche was accompanied by a refusal of Spanish Justice Minister Rafael Catala to attend a Downing Street reception arranged on the eve of an anti-corruption summit organized by Prime Minister David Cameron.

“It is shameful that Spain is treating a NATO ally in this fashion, yet all we do is to send diplomatic notes or call in the Spanish Ambassador,” the Sunday Express quoted MP Andrew Rosindell, chairman of the British Overseas Territories and Crown Dependencies All Party Parliamentary Groups, as saying.

Gibraltar enjoys wide autonomy, but the exclave’s defense issues and foreign relations are taken care of in London.

Source: MENA