The Spanish Minister for Foreign Affairs says the joint use of Gibraltar airport is an element of the treaty which has been decided.
Jose Manuel Albares says he remains optimistic that an agreement will be reached - but he says that nothing has been agreed to yet. Mr Albares however reiterates that all parties have now moved closer to agreeing on a number of important issues.
The Spanish Foreign Minister says that while there has been a consensus on a number of important issues - such as free movement of people and goods, and the joint use of the airport - an agreement has yet to be reached.
Jose Manuel Albares says he cannot quote an end date to the ongoing negotiations, because no end date has been set.
In an interview with Europa Sur and the Grupo Joly, he says the joint use of the airport would see a return of flights to Spanish destinations such as Madrid and Barcelona. .
On the issue of free movement of people and goods, Mr Albares says Gibraltar would enjoy some form of access to the Schengen area and the Customs Union - and that this would be managed by Frontex officers who would support Spanish Police during a transitional period.
Asked how joint use of the airport could impact on the military aspects managed by the Ministry of Defence, the Spanish Minister for Foreign Affairs said he could not go into such details.
On the issue of the military base, Mr Albares said that the UK and Spain are both members of NATO and that they are committed to working together as NATO partners to avoid the conflicts of the past.
Asked about other matters, Jose Manuel Albares said the treaty would create a zone of shared prosperity, and that this in its own right would do away with issues such as smuggling, marked pricing differences and fraud.
The Spanish Foreign Minister also reiterated that a treaty would not compromise Spain’s sovereignty claim over Gibraltar, which he said, remains alive.