And although illness forced Lady Thatcher to step out of the limelight, it did not stop her making her increasingly outspoken views on the EU known.
It would be more accurate, though perhaps a little unkind, to say "And although dementia forced Lady Thatcher to step out of the limelight, it did not stop her making her increasingly outspoken views on the EU known"
Perhaps you're right, and there is a link between failing mental powers, and hatred of the EU.

