Jane Merrick is a British political journalist and former political editor of the Independent on Sunday newspaper. The opinions expressed in this commentary are hers.

(CNN) There are now 100 days to go until the United Kingdom is due to leave the European Union, and Theresa May is no closer to securing parliamentary backing for the terms of Brexit.

If that approval never comes, Britain leaves the EU on March 29 without a deal: There would be no customs arrangements with its closest neighbors and trading partners; The normally free-flowing supply routes from Europe into the UK for food, medicine and other essential goods and services would become blocked; British citizens living and working in the EU would lose their legal status.

It would, by any sensible prediction, have a severe impact on the daily lives of everyone in the country from the moment they wake up on March 30. This fast-looming deadline has suddenly motivated the Prime Minister and her Cabinet into launching contingency plans so the country will be able to cope. Yet the government has, surely, acted too late -- 14 weeks is not enough time to put in place the infrastructure needed for the UK to go onto an emergency footing.

The problem with May's decision to order no-deal contingency planning so late in the day is that it is being seen as a politically motivated ruse to get members of Parliament, or MPs, to back her Brexit deal, agreed to last month by EU leaders. By dismissing suggestions for other alternative plans, such as a model based on Norway's relationship with the EU, the Prime Minister is indeed forcing Parliament to choose between her plan or no deal. The opposition Labour Party say it's not going to fall for it, describing the sudden implementation of no-deal contingencies as a "political hoax."

And yet the entire story of Brexit can be told through the misconceived idea that the least likely option will never happen. In the run-up to the 2016 referendum, the polls, the media and politicians all predicted the country would vote to remain in the EU -- and were stunned when 17.4 million people voted to leave.

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