There had been widespread speculation that Mid Bedfordshire MP had been contemplating a move to UKIP.
However, it is understood the Ukip issue did not come up at her meeting with Sir George this afternoon, which was described as "convivial".
Ms Dorries said: "I am delighted. It is long overdue."
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Dry overnight with clear spells but becoming chilly with a frost forming. Misty with areas of dense freezing fog likely by morning.
Shots were fired by US service personnel and a man has been detained after a disturbance at RAF Mildenhall, Suffolk Police said.
Police in Suffolk have confirmed they're dealing with a "significant incident" at RAF Mildenhall.