Maggie got stabbed in the back and tossed by her own party, at the behest of the Build-a-Burgers, over the monetary-union issue. The Burgers wanted England to give up the pound sterling and go into the euro. Maggie told them "piss off", and some moral midgets in her own party launched the coup, the will of the Burgers for to build.
I finished reading her memoirs a little while back. She went into great detail about the monetary-union issue and the EU, along with everything else she dealt with during her time. Good read!