She was reacting to the news that The Office for National Statistics was considering declaring your sex could be optional in the next census under proposals aimed at recognising transgender people.
Reports suggest the 2021 national survey could make the gender question voluntary.
Mrs Parker, MEP for the East Midlands, said: “This is madness. I am sorry but this is taking the whole ‘PC factor’ too far.
“We won’t know precise figures for men and women as we move forward. It would mean no accurate data on the make-up of the country at all. How can we plan for the future and allocate resources?
“It would skew figures on health, wages, population forecasts and many other crucial factors the country needs to progress and plan for the future.
“The most basic of data will be snatched away – when will this end? We cannot keep protecting the feelings of the very few at the expense of the many.
“I am certain leaving a explanatory box on the forms for people to explain if they are transgender would suffice.”