Julie Girling, MEP for South West England and Gibraltar, told ITV News that locals had "no hope that things are going to get better soon."
Delays at the Spanish Gibraltar border were "entirely pre-meditated to cause the maximum disruption," she said.
She added that Spanish social media users had been using Twitter to insult her "personal experience, my private life, my health" but that she would not give up fighting for the Gibraltarians.
It may be a pre-planned training exercise but what timing: UK warships sail through disputed water to Her Majesty's naval base on Gibraltar.
Spain could damage to the economy in Gibraltar, but in doing so it would harm its own, so a further escalation of threats is unlikely.
The PM has said he is seriously concerned by Spain's plans to introduce a levy at the border with Gibraltar.