Another of the Anglia region's MEPs has defected from the UK Independence Party to the Conservatives.
Marta Andreasen, who represents the South East which includes Milton Keynes, quit UKIP and launched an outspoken attack on Nigel Farage's leadership.
She dismissed the party's chances of achieving real power, and hailed the Prime Minister's speech pledging an in-out referendum on EU membership as a "game changer".
In an open letter Ms Andreasen wrote: "UKIP has good people in it at grass roots that care about the future of the United Kingdom and our place in a re-negotiated relationship with Europe. Unfortunately, their party leader treats any views other than his own with contempt."
In May 2011 one of the MEPs for the East of England, David Campbell Bannerman, also switched sides from UKIP to the Conservatives.