Andy McSmith: From Churchill to Sir Keith Joseph, we've been in this territory before

Howard Flight is not the first Conservative politician to worry about the wrong people having children. The idea that the welfare state encourages young women with no better prospects to get pregnant and live off benefits is always around, but is seldom expressed so bluntly.

The most famous example of a Tory politician blundering into this territory was when the former Social Security Secretary, Sir Keith Joseph, was campaigning to be leader of the Conservative Party in October 1974. "The balance of our human stock is threatened. A high and rising proportion of children are being born to mothers least fitted to bring children into the world," he said in a speech.

"They are producing problem children, the future unmarried mothers, delinquents, denizens of our borstals." Sir Keith's leadership aspirations collapsed under a heap of ridicule, opening the way for his friend Margaret Thatcher.

Others have expressed similar thoughts without in any way damaging their standing within the Conservative Party. Addressing the Conservative Party conference in October 1992, Peter Lilley, who was then Secretary of State for Social Security, attacked "young ladies who get pregnant just to jump the housing list".

After visiting a council estate the following July, the Welsh Secretary, John Redwood, complained: "In that community people had begun to accept that babies just happened and there was no presumption in favour of creating a loving family background for their children. It is that which we have to change."

All this is mild compared with the ideas that were in fashion in 1912, when 750 delegates crowded into a hall in London for the first International Eugenics Conference, to discuss the fashionable fear that inferior people were having too many children.

Winston Churchill was particularly exercised by this problem. "I am convinced that the multiplication of the feeble-minded... is a terrible danger to the race," he once wrote.

This was not, then, just a right wing fad. Churchill was a Liberal. His fears were shared by the socialist Sidney Webb, who wrote in a Fabian tract in 1907: "In Great Britain at this moment... children are being freely born to the Irish Roman Catholics and the Polish, Russian and German Jews, the thriftless and irresponsible... This can hardly result in anything but national deterioration."