A Downing Street spokesperson said:
The Prime Minister has called President Barroso to raise serious concerns that additional border checks introduced by the Spanish at the Spain-Gibraltar border are politically motivated and disproportionate, and therefore contrary to the EU right of free movement.
The PM made clear that we would prefer to resolve this issue through political dialogue. Consequently, both the PM and the Foreign Secretary had called their Spanish counterparts to try to find a way to de-escalate the issue. And we have also proposed ad-hoc talks, involving the government of Gibraltar, to find a solution. The PM explained that despite these efforts, the additional border measures continue and therefore we are now actively considering legal action and collating evidence on the sporadic nature of these measures which would prove that they are illegitimate.
In the meantime, we believe that the European Commission, as guardian of the treaties, should investigate the issue and the PM called on President Barroso to send an EU monitoring team to the Gibraltar-Spain border urgently to gather evidence of the checks that are being carried out. The PM emphasised that the Commission has a responsibility to do this as part of its role overseeing the application of Union law. President Barroso responded that the European Commission are closely monitoring the situation and that, following a thorough legal assessment, they would not hesitate to take any measures necessary to uphold EU law.
The Deputy Prime Minister will be calling the Spanish DPM, Soraya Saenz de Santamaria, later this afternoon to reiterate our concerns and to press for a way forward to de-escalate the issue.
Finally, the PM took the opportunity of the call to President Barroso to raise our concerns about the situation in Egypt. They agreed on the need for the EU to send a strong and united message that the violence must end and that there should be transition to a genuine democracy, which would require compromise from all sides. They also agreed that the EU should take a similarly tough and united position on the elections in Zimbabwe ahead of the SADC summit this weekend.