I found there was no central record to show occasions where covert baggage searches were carried out, but no seizures were made.
The absence of these records meant that no assurance could be provided to demonstrate that this power was being used in a lawful, proportionate and controlled manner.
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The chancellor now faces the prospect of forming a minority government or calling for a snap election.
The 73-year-old said a return is unlikely "given the politicised atmosphere that seems to have afflicted our set."
Chancellor Philip Hammond said the UK will make a financial proposal to the EU in the next three-and-a-half weeks.