If Thatcher had her way the EU would just be an trade bloc as well and not a political union which would have been extremely based .
It is
still fundamentally a trade bloc and she was responsible for much of the tighter integration during the 1980s. Her shift to a more hostile stance in her final years in office* was a complete repudiation of everything she had argued on the European issue in her long career, which is why it initially blindsided Brussels so much.
*Also the point at which her rapid cognitive decline due to early-onset Alzheimer's became quite grimly apparent in hindsight. I would personally be wary of drawing a direct link between the two things as there are alternative explanations that work just as well, but it is always something to be aware of with regards to the twilight of her career and some of the more surprising decisions she made at the time.
Poll
