Diana Wallis MEP sent a statement of support to the protesters gathered at the US spy base in Menwith Hill, North Yorkshire on Saturday.
The Campaign for the Accountability of American Bases who organised the demonstration objects to the base's links to the so-called "Star Wars" programme.
In her statement Diana, who has spoken at previous demonstrations at Menwith, said:
"Where is the outrage from Britain's right-wing press, politicians and commentators over the transfer of British sovereignty in crucial areas of national security to the United States? Whenever it comes to power-sharing in Europe they have an unshakeable habit of working themselves into a fury.
"They like to portray themselves as the great defenders of British sovereignty. Yet those same people remain largely silent when the government allows the continuation of American enclaves on British soil, protected from Parliamentary scrutiny or public debate.
"In a three-paragraph written statement slipped out in July, just one day before Parliament rose - and almost completely unnoticed by the press - the Defence Secretary announced that the Government is permitting the US administration to install additional equipment here at Menwith Hill, to support its unproven missile defence system.
"There has been no public debate in Britain about the desirability, or workability of missile defence, let alone about the strategic assumptions that underpin it. The American programme has suffered from successive test failures and critical Congressional reports over the past 20 years.
"Parliamentary scrutiny is denied or obstructed in the name of national interest. It is inconceivable that if circumstances were reversed, the US Congress would tolerate such limitations on its powers. The British Parliament seems supine in comparison.
"Those who defend against the infringement of British sovereignty should take note of this issue, rather than battering at the compromises British Ministers make in European negotiations. Others, in cosy consensus, justify the use of UK bases as extra-territorial enclaves that serve American ends.
2The drive towards missile defence in Washington is driven by a mixture of industrial and military interests, and the identification of Iran as an existential enemy of the West. The British Parliament has the duty to question whether such motivations are compatible with British national interests."
Follow the party's activity on...