The UK Independence Party MEP Marta Andreasen has defected to the Conservatives.
She alleges that UKIP leader Nigel Farage "treats any views other than his own with contempt."
She adds: "Essentially, I do not see the party being led to achieve presence in Westminster which is the place where decisions can be made to stop the EU juggernaut."
Ms Andreasen says she was convinced to switch to the Conservatives after David Cameron's "game changer" speech on Britain's relations with Europe, pledging an in-out referendum on the issue.
"I was also reassured by the financial deal that David Cameron got for Britain on the EU Budget", she added.
More top news
The actress said film-makers doubted if she could play a straight woman in a romantic lead after speaking publicly about her sexuality.
Owen Lambert, 18, and his friends were on a university trip to Parliament when they were hit by the Westminster attacker's speeding car.
Teenage blogger Amos Yee from Singapore was jailed for posting criticisms of his government online.